密钥K出现在数组中的概率-yiteyi-C++库

给定一个数组A[]，数组的大小为N，另一个密钥为K。任务是找到密钥K出现在数组中的概率。 例如：

null

Input : N = 6        A[] = { 4, 7, 2, 0, 8, 7, 5 }        K = 3Output :0Since value of k = 3  is not present in array,hence the probability of 0.Input :N = 10       A[] = { 2, 3, 5, 1, 9, 8, 0, 7, 6, 5 }       K = 5Output :0.2

推荐：请尝试你的方法 {IDE} 首先，在进入解决方案之前。

可使用以下公式计算出发生故障的概率：

Probability = total number of K present /                          size of array.

首先，计算K的数量，然后概率将是K的数量除以N，即计数/N。以下是上述方法的实施情况：

C++

                         // C++ code to find the probability of                       
                         // search key K present in array                       
                         #include <bits/stdc++.h>                       
                         using                                     namespace                                     std;                       
           
                         // Function to find the probability                       
                         float                                     kPresentProbability(                                     int                                     a[],                                     int                                     n,                                     int                                     k)                       
                         {                       
                                                 float                                     count = 0;                       
           
                                                 for                                     (                                     int                                     i = 0; i < n; i++)                       
                                                 if                                     (a[i] == k)                       
                                                 count++;                       
           
                                                 // find probability                       
                                                 return                                     count / n;                       
                         }                       
           
                         // Driver Code                       
                         int                                     main()                       
                         {                       
           
                                                 int                                     A[] = { 4, 7, 2, 0, 8, 7, 5 };                       
                                                 int                                     K = 3;                       
                                                 int                                     N =                                     sizeof                                     (A) /                                     sizeof                                     (A[0]);                       
                                                 cout << kPresentProbability(A, N, K);                       
                                                 return                                     0;                       
                         }                       

Python3

                         # Python3 code to find the                       
                         # probability of search key                       
                         # K present in 1D-array (list).                       
           
                         # Function to find the probability                       
                         def                                     kPresentProbability(a, n, k) :                       
           
                                                 count                                     =                                     a.count(k)                       
           
                                                 # find probability upto                       
                                                 # 2 decimal places                       
                                                 return                                     round                                     (count                                     /                                     n ,                                     2                                     )                       
           
                         # Driver Code                       
                         if                                     __name__                                     =                                     =                                     "__main__"                                     :                       
                                   
                                                 A                                     =                                     [                                     4                                     ,                                     7                                     ,                                     2                                     ,                                     0                                     ,                                     8                                     ,                                     7                                     ,                                     5                                     ]                       
                                                 K                                     =                                     2                       
                                                 N                                     =                                     len                                     (A)                       
                                   
                                                 print                                     (kPresentProbability( A, N, K))                       
           
                         # This code is contributed                       
                         # by AnkitRai1                       

JAVA

                         // Java code to find the probability                       
                         // of search key K present in array                       
                         class                                     GFG                       
                         {                       
           
                         // Function to find the probability                       
                         static                                     float                                     kPresentProbability(                                     int                                     a[],                       
                                                 int                                     n,                       
                                                 int                                     k)                       
                         {                       
                                                 float                                     count =                                     0                                     ;                       
                                   
                                                 for                                     (                                     int                                     i =                                     0                                     ; i < n; i++)                       
                                                 if                                     (a[i] == k)                       
                                                 count++;                       
                                   
                                                 // find probability                       
                                                 return                                     count/ n;                       
                         }                       
           
                         // Driver Code                       
                         public                                     static                                     void                                     main(String[] args)                       
                         {                       
                                                 int                                     A[] = {                                     4                                     ,                                     7                                     ,                                     2                                     ,                                     0                                     ,                                     8                                     ,                                     7                                     ,                                     5                                     };                       
                                                 int                                     K =                                     2                                     ;                       
                                                 int                                     N = A.length;                       
                                                 double                                     n = kPresentProbability(A, N, K);                       
                                                 double                                     p = (                                     double                                     )Math.round(n *                                     100                                     ) /                                     100                                     ;                       
                                                 System.out.println(p);                       
                         }                       
                         }                       
           
                         // This code is contributed                       
                         // by ChitraNayal                       

C#

                         // C# code to find the probability                       
                         // of search key K present in array                       
                         using                                     System;                       
           
                         class                                     GFG                       
                         {                       
           
                         // Function to find the probability                       
                         static                                     float                                     kPresentProbability(                                     int                                     [] a,                       
                                                 int                                     n,                       
                                                 int                                     k)                       
                         {                       
                                                 float                                     count = 0;                       
                                   
                                                 for                                     (                                     int                                     i = 0; i < n; i++)                       
                                                 if                                     (a[i] == k)                       
                                                 count++;                       
                                   
                                                 // find probability                       
                                                 return                                     count/ n;                       
                         }                       
           
                         // Driver Code                       
                         public                                     static                                     void                                     Main()                       
                         {                       
                                                 int                                     [] A = { 4, 7, 2, 0, 8, 7, 5 };                       
                                                 int                                     K = 2;                       
                                                 int                                     N = A.Length;                       
                                                 double                                     n = kPresentProbability(A, N, K);                       
                                                 double                                     p = (                                     double                                     )Math.Round(n * 100) / 100;                       
                                                 Console.Write(p);                       
                         }                       
                         }                       
           
                         // This code is contributed                       
                         // by ChitraNayal                       

PHP

                         <?php                       
                         // PHP code to find the probability                       
                         // of search key K present in array                       
           
                         // Function to find the probability                       
                         function                                     kPresentProbability(&                                     $a                                     ,                                     $n                                     ,                                     $k                                     )                       
                         {                       
                                                 $count                                     = 0;                       
           
                                                 for                                     (                                     $i                                     = 0;                                     $i                                     <                                     $n                                     ;                                     $i                                     ++)                       
                                                 if                                     (                                     $a                                     [                                     $i                                     ] ==                                     $k                                     )                       
                                                 $count                                     ++;                       
           
                                                 // find probability                       
                                                 return                                     $count                                     /                                     $n                                     ;                       
                         }                       
           
                         // Driver Code                       
                         $A                                     =                                     array                                     ( 4, 7, 2, 0, 8, 7, 5 );                       
                         $K                                     = 2;                       
                         $N                                     = sizeof(                                     $A                                     );                       
                         echo                                     round                                     (kPresentProbability(                                     $A                                     ,                                     $N                                     ,                                     $K                                     ), 2);                       
           
                         // This code is contributed                       
                         // by ChitraNayal                       
                         ?>                       

Javascript

                         <script>                       
                         // JavaScript code to find the probability of                       
                         // search key K present in array                       
           
                         // Function to find the probability                       
                         function                                     kPresentProbability(a,n,k)                       
                         {                       
                                                 let count = 0;                       
           
                                                 for                                     (let i = 0; i < n; i++)                       
                                                 if                                     (a[i] == k)                       
                                                 count+=1;                       
                                                 // find probability                       
                                                 return                                     count / n;                       
                         }                       
           
                         // Driver Code                       
           
                                                 let A = [ 4, 7, 2, 0, 8, 7, 5 ];                       
                                                 let K = 3;                       
                                                 let N = A.length;                       
                                                 document.write(kPresentProbability(A, N,K));                       
                                   
                         // This code contributed by Rajput-Ji                       
           
                         </script>                       

输出

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