数字之和为十的第n个数-yiteyi-C++库

给定一个整数值n，求出其和为10的第n个正整数。 例如：

null

Input: n = 2
Output: 28
The first number with sum of digits as
10 is 19. Second number is 28.

Input: 15
Output: 154

推荐：请尝试你的方法 {IDE} 首先，在进入解决方案之前。

方法1（简单）： 我们遍历所有数字。对于每一个数字，我们都会找到数字之和。当我们找到第n个数字，数字之和为10时，我们停止。

C++

                         // Simple CPP program to find n-th number                       
                         // with sum of digits as 10.                       
                         #include <bits/stdc++.h>                       
                         using                                     namespace                                     std;                       
                                   
                         int                                     findNth(                                     int                                     n)                       
                         {                       
                                                 int                                     count = 0;                       
                                   
                                                 for                                     (                                     int                                     curr = 1;; curr++) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 int                                     sum = 0;                       
                                                 for                                     (                                     int                                     x = curr; x > 0; x = x / 10)                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return current                       
                                                 // number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                         int                                     main()                       
                         {                       
                                                 printf                                     (                                     "%d"                                     , findNth(5));                       
                                                 return                                     0;                       
                         }                       

JAVA

                         // Java program to find n-th number                       
                         // with sum of digits as 10.                       
                                   
                         import                                     java.util.*;                       
                         import                                     java.lang.*;                       
                                   
                         public                                     class                                     GFG {                       
                                                 public                                     static                                     int                                     findNth(                                     int                                     n)                       
                                                 {                       
                                                 int                                     count =                                     0                                     ;                       
                                                 for                                     (                                     int                                     curr =                                     1                                     ;; curr++) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 int                                     sum =                                     0                                     ;                       
                                                 for                                     (                                     int                                     x = curr; x >                                     0                                     ; x = x /                                     10                                     )                       
                                                 sum = sum + x %                                     10                                     ;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum ==                                     10                                     )                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return current                       
                                                 // number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 }                       
                                   
                                                 public                                     static                                     void                                     main(String[] args)                       
                                                 {                       
                                                 System.out.print(findNth(                                     5                                     ));                       
                                                 }                       
                         }                       
                                   
                         // Contributed by _omg                       

Python3

                         # Python3 program to find n-th number                       
                         # with sum of digits as 10.                       
                         import                                     itertools                       
                                   
                         # function to find required number                       
                         def                                     findNth(n):                       
                                   
                                                 count                                     =                                     0                       
                                   
                                                 for                                     curr                                     in                                     itertools.count():                       
                                                 # Find sum of digits in current no.                       
                                                 sum                                     =                                     0                       
                                                 x                                     =                                     curr                       
                                                 while                                     (x):                       
                                                 sum                                     =                                     sum                                     +                                     x                                     %                                     10                       
                                                 x                                     =                                     x                                     /                                     /                                     10                       
                                   
                                                 # If sum is 10, we increment count                       
                                                 if                                     (                                     sum                                     =                                     =                                     10                                     ):                       
                                                 count                                     =                                     count                                     +                                     1                       
                                   
                                                 # If count becomes n, we return current                       
                                                 # number.                       
                                                 if                                     (count                                     =                                     =                                     n):                       
                                                 return                                     curr                       
                                   
                                                 return                                     -                                     1                       
                                   
                         # Driver program                       
                         if                                     __name__                                     =                                     =                                     '__main__'                                     :                       
                                                 print                                     (findNth(                                     5                                     ))                       
                                   
                         # This code is contributed by                       
                         # Sanjit_Prasad                       

C#

                         // C# program to find n-th number                       
                         // with sum of digits as 10.                       
                         using                                     System;                       
                                   
                         class                                     GFG {                       
                                                 public                                     static                                     int                                     findNth(                                     int                                     n)                       
                                                 {                       
                                                 int                                     count = 0;                       
                                                 for                                     (                                     int                                     curr = 1;; curr++) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 int                                     sum = 0;                       
                                                 for                                     (                                     int                                     x = curr; x > 0; x = x / 10)                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we                       
                                                 // return current number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 }                       
                                   
                                                 // Driver Code                       
                                                 static                                     public                                     void                                     Main()                       
                                                 {                       
                                                 Console.WriteLine(findNth(5));                       
                                                 }                       
                         }                       
                                   
                         // This code is contributed                       
                         // by Sach_Code                       

PHP

                         <?php                       
                         // Simple PHP program to find n-th                       
                         // number with sum of digits as 10.                       
                         function                                     findNth(                                     $n                                     )                       
                         {                       
                                                 $count                                     = 0;                       
                                   
                                                 for                                     (                                     $curr                                     = 1; ;                                     $curr                                     ++)                       
                                                 {                       
                                   
                                                 // Find sum of digits in                       
                                                 // current no.                       
                                                 $sum                                     = 0;                       
                                                 for                                     (                                     $x                                     =                                     $curr                                     ;                       
                                                 $x                                     > 0;                                     $x                                     =                                     $x                                     / 10)                       
                                                 $sum                                     =                                     $sum                                     +                                     $x                                     % 10;                       
                                   
                                                 // If sum is 10, we increment                       
                                                 // count                       
                                                 if                                     (                                     $sum                                     == 10)                       
                                                 $count                                     ++;                       
                                   
                                                 // If count becomes n, we return                       
                                                 // current number.                       
                                                 if                                     (                                     $count                                     ==                                     $n                                     )                       
                                                 return                                     $curr                                     ;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                         // Driver Code                       
                         echo                                     findNth(5);                       
                                   
                         // This code is contributed by Sach .                       
                         ?>                       

Javascript

                         <script>                       
                                   
                         // Simple JavaScript program to find n-th number                       
                         // with sum of digits as 10.                       
                                   
                         function                                     findNth(n)                       
                         {                       
                                                 let count = 0;                       
                                   
                                                 for                                     (let curr = 1;; curr++) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 let sum = 0;                       
                                                 for                                     (let x = curr; x > 0; x = Math.floor(x / 10))                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return current                       
                                                 // number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                                   
                                                 document.write(findNth(5));                       
                                   
                                   
                         // This code is contributed by Surbhi Tyagi.                       
                                   
                         </script>                       

输出

方法2（高效）： 如果我们仔细观察，我们会发现所有9的倍数都出现在算术级数19，28，37，46，55，64，73，82，91，100，109，… 然而，上述系列中有一些数字的数字总和不是10，例如100。因此，我们不是逐个检查，而是从19开始，递增9。

C++

                         // Simple CPP program to find n-th number                       
                         // with sum of digits as 10.                       
                         #include <bits/stdc++.h>                       
                         using                                     namespace                                     std;                       
                                   
                         int                                     findNth(                                     int                                     n)                       
                         {                       
                                                 int                                     count = 0;                       
                                   
                                                 for                                     (                                     int                                     curr = 19;; curr += 9) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 int                                     sum = 0;                       
                                                 for                                     (                                     int                                     x = curr; x > 0; x = x / 10)                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return current                       
                                                 // number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                         int                                     main()                       
                         {                       
                                                 printf                                     (                                     "%d"                                     , findNth(5));                       
                                                 return                                     0;                       
                         }                       

JAVA

                         // Java program to find n-th number                       
                         // with sum of digits as 10.                       
                                   
                         import                                     java.util.*;                       
                         import                                     java.lang.*;                       
                                   
                         public                                     class                                     GFG {                       
                                                 public                                     static                                     int                                     findNth(                                     int                                     n)                       
                                                 {                       
                                                 int                                     count =                                     0                                     ;                       
                                   
                                                 for                                     (                                     int                                     curr =                                     19                                     ;; curr +=                                     9                                     ) {                       
                                   
                                                 // Find sum of digits in current no.                       
                                                 int                                     sum =                                     0                                     ;                       
                                                 for                                     (                                     int                                     x = curr; x >                                     0                                     ; x = x /                                     10                                     )                       
                                                 sum = sum + x %                                     10                                     ;                       
                                   
                                                 // If sum is 10, we increment count                       
                                                 if                                     (sum ==                                     10                                     )                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return current                       
                                                 // number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 }                       
                                   
                                                 public                                     static                                     void                                     main(String[] args)                       
                                                 {                       
                                                 System.out.print(findNth(                                     5                                     ));                       
                                                 }                       
                         }                       
                                   
                         // Contributed by _omg                       

Python3

                         # Python3 program to find n-th                       
                         # number with sum of digits as 10.                       
                         def                                     findNth(n):                       
                                                 count                                     =                                     0                                     ;                       
                                   
                                                 curr                                     =                                     19                                     ;                       
                                   
                                                 while                                     (                                     True                                     ):                       
                                   
                                                 # Find sum of digits in                       
                                                 # current no.                       
                                                 sum                                     =                                     0                                     ;                       
                                                 x                                     =                                     curr;                       
                                                 while                                     (x >                                     0                                     ):                       
                                                 sum                                     =                                     sum                                     +                                     x                                     %                                     10                                     ;                       
                                                 x                                     =                                     int                                     (x                                     /                                     10                                     );                       
                                   
                                                 # If sum is 10, we increment                       
                                                 # count                       
                                                 if                                     (                                     sum                                     =                                     =                                     10                                     ):                       
                                                 count                                     +                                     =                                     1                                     ;                       
                                   
                                                 # If count becomes n, we return                       
                                                 # current number.                       
                                                 if                                     (count                                     =                                     =                                     n):                       
                                                 return                                     curr;                       
                                   
                                                 curr                                     +                                     =                                     9                                     ;                       
                                   
                                                 return                                     -                                     1                                     ;                       
                                   
                         # Driver Code                       
                         print                                     (findNth(                                     5                                     ));                       
                                   
                         # This code is contributed                       
                         # by mits                       

C#

                         // C# program to find n-th number                       
                         // with sum of digits as 10.                       
                         using                                     System;                       
                                   
                         class                                     GFG {                       
                                                 public                                     static                                     int                                     findNth(                                     int                                     n)                       
                                                 {                       
                                                 int                                     count = 0;                       
                                   
                                                 for                                     (                                     int                                     curr = 19;; curr += 9) {                       
                                   
                                                 // Find sum of digits in                       
                                                 // current no.                       
                                                 int                                     sum = 0;                       
                                                 for                                     (                                     int                                     x = curr;                       
                                                 x > 0; x = x / 10)                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment                       
                                                 // count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return                       
                                                 // current number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 }                       
                                   
                                                 // Driver Code                       
                                                 static                                     public                                     void                                     Main()                       
                                                 {                       
                                                 Console.WriteLine(findNth(5));                       
                                                 }                       
                         }                       
                                   
                         // This code is contributed                       
                         // by Sach_Code                       

PHP

                         <?php                       
                         // Simple PHP program to find n-th                       
                         // number with sum of digits as 10.                       
                         function                                     findNth(                                     $n                                     )                       
                         {                       
                                                 $count                                     = 0;                       
                                   
                                                 for                                     (                                     $curr                                     = 19; ;                                     $curr                                     += 9)                       
                                                 {                       
                                   
                                                 // Find sum of digits in                       
                                                 // current no.                       
                                                 $sum                                     = 0;                       
                                                 for                                     (                                     $x                                     =                                     $curr                                     ;                                     $x                                     > 0;                       
                                                 $x                                     = (int)                                     $x                                     / 10)                       
                                                 $sum                                     =                                     $sum                                     +                                     $x                                     % 10;                       
                                   
                                                 // If sum is 10, we increment                       
                                                 // count                       
                                                 if                                     (                                     $sum                                     == 10)                       
                                                 $count                                     ++;                       
                                   
                                                 // If count becomes n, we return                       
                                                 // current number.                       
                                                 if                                     (                                     $count                                     ==                                     $n                                     )                       
                                                 return                                     $curr                                     ;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                         // Driver Code                       
                         echo                                     findNth(5);                       
                                   
                         // This code is contributed                       
                         // by Sach_Code                       
                         ?>                       

Javascript

                         <script>                       
                                   
                         // Simple Javascript program to find n-th                       
                         // number with sum of digits as 10.                       
                         function                                     findNth(n)                       
                         {                       
                                                 let count = 0;                       
                                   
                                                 for                                     (let curr = 19; ;curr += 9)                       
                                                 {                       
                                   
                                                 // Find sum of digits in                       
                                                 // current no.                       
                                                 let sum = 0;                       
                                                 for                                     (let x = curr; x > 0;                       
                                                 x = parseInt(x / 10))                       
                                                 sum = sum + x % 10;                       
                                   
                                                 // If sum is 10, we increment                       
                                                 // count                       
                                                 if                                     (sum == 10)                       
                                                 count++;                       
                                   
                                                 // If count becomes n, we return                       
                                                 // current number.                       
                                                 if                                     (count == n)                       
                                                 return                                     curr;                       
                                                 }                       
                                                 return                                     -1;                       
                         }                       
                                   
                         // Driver Code                       
                         document.write(findNth(5));                       
                                   
                         // This code is contributed                       
                         // by gfgking                       
                         </script>                       

输出

文章版权归作者所有，未经允许请勿转载。

THE END

技术文章