信用卡号码验证程序-yiteyi-C++库

编写一个程序，提示用户以长整数形式输入信用卡号，并显示该卡是否有效。 信用卡号码遵循一定的模式。信用卡号必须在13到16位之间。它必须从以下方面开始：

null

4.Visa卡
5张万事达卡
37张美国运通卡
6.探索卡

这个问题可以通过使用卢恩算法 . 卢恩支票 或者 Mod 10 检查，可描述如下（用于说明，考虑卡号4388576018402626）： 第一步 .从右到左每隔两位数。如果数字加倍会导致两位数，将两位数相加得到一个位数（如12:1+2，18=1+8）。 第二步 .现在将步骤1中的所有单位数相加。 4 + 4 + 8 + 2 + 3 + 1 + 7 + 8 = 37 第三步 .在卡号中从右到左的奇数处添加所有数字。 6 + 6 + 0 + 8 + 0 + 7 + 8 + 3 = 38 第四步 .将步骤2和步骤3的结果相加。 37 + 38 = 75 第五步 .如果步骤4的结果可被10整除，则卡号有效；否则无效。 例如：

Input : 379354508162306Output : 379354508162306 is ValidInput : 4388576018402626Output : 4388576018402626 is invalid

推荐：请尝试你的方法 {IDE} 首先，在进入解决方案之前。

C++

                         // C++ program to check if a given credit                       
                         // card is valid or not.                       
                         #include <iostream>                       
                         using                                     namespace                                     std;                       
           
                         // Return this number if it is a single digit, otherwise,                       
                         // return the sum of the two digits                       
                         int                                     getDigit(                                     int                                     number)                       
                         {                       
                                                 if                                     (number < 9)                       
                                                 return                                     number;                       
                                                 return                                     number / 10 + number % 10;                       
                         }                       
           
                         // Return the number of digits in d                       
                         int                                     getSize(                                     long                                     d)                       
                         {                       
                                                 string num = to_string(d);                       
                                                 return                                     num.length();                       
                         }                       
           
                         // Return the first k number of digits from                       
                         // number. If the number of digits in number                       
                         // is less than k, return number.                       
                         long                                     getPrefix(                                     long                                     number,                                     int                                     k)                       
                         {                       
                                                 if                                     (getSize(number) > k)                       
                                                 {                       
                                                 string num = to_string(number);                       
                                                 return                                     stol(num.substr(0, k));                       
                                                 }                       
                                                 return                                     number;                       
                         }                       
           
                         // Return true if the digit d is a prefix for number                       
                         bool                                     prefixMatched(                                     long                                     number,                                     int                                     d)                       
                         {                       
                                                 return                                     getPrefix(number, getSize(d)) == d;                       
                         }                       
           
                         // Get the result from Step 2                       
                         int                                     sumOfDoubleEvenPlace(                                     long                                     int                                     number)                       
                         {                       
                                                 int                                     sum = 0;                       
                                                 string num = to_string(number) ;                       
                                                 for                                     (                                     int                                     i = getSize(number) - 2; i >= 0; i -= 2)                       
                                                 sum += getDigit(                                     int                                     (num[i] -                                     '0'                                     ) * 2);                       
           
                                                 return                                     sum;                       
                         }                       
           
                         // Return sum of odd-place digits in number                       
                         int                                     sumOfOddPlace(                                     long                                     number)                       
                         {                       
                                                 int                                     sum = 0;                       
                                                 string num = to_string(number) ;                       
                                                 for                                     (                                     int                                     i = getSize(number) - 1; i >= 0; i -= 2)                       
                                                 sum += num[i] -                                     '0'                                     ;                       
                                                 return                                     sum;                       
                         }                       
           
                         // Return true if the card number is valid                       
                         bool                                     isValid(                                     long                                     int                                     number)                       
                         {                       
                                                 return                                     (getSize(number) >= 13 &&                       
                                                 getSize(number) <= 16) &&                       
                                                 (prefixMatched(number, 4) ||                       
                                                 prefixMatched(number, 5) ||                       
                                                 prefixMatched(number, 37) ||                       
                                                 prefixMatched(number, 6)) &&                       
                                                 ((sumOfDoubleEvenPlace(number) +                       
                                                 sumOfOddPlace(number)) % 10 == 0);                       
                         }                       
           
                         // Driver Code                       
                         int                                     main()                       
                         {                       
                                                 long                                     int                                     number = 5196081888500645L;                       
                                                 cout << number <<                                     " is "                                     <<  (isValid(number) ?                                     "valid"                                     :                                     "invalid"                                     );                       
                                                 return                                     0;                       
                         }                       
           
                         // This code is contributed by yuvraj_chandra                       

JAVA

                         // Java program to check if a given credit                       
                         // card is valid or not.                       
                         import                                     java.util.Scanner;                       
           
                         public                                     class                                     CreditCard {                       
                                                 // Main Method                       
                                                 public                                     static                                     void                                     main(String[] args)                       
                                                 {                       
                                                 long                                     number = 5196081888500645L;                       
           
                                                 System.out.println(number +                                     " is "                                     +                       
                                                 (isValid(number) ?                                     "valid"                                     :                                     "invalid"                                     ));                       
                                                 }                       
           
                                                 // Return true if the card number is valid                       
                                                 public                                     static                                     boolean                                     isValid(                                     long                                     number)                       
                                                 {                       
                                                 return                                     (getSize(number) >=                                     13                                     &&                       
                                                 getSize(number) <=                                     16                                     ) &&                       
                                                 (prefixMatched(number,                                     4                                     ) ||                       
                                                 prefixMatched(number,                                     5                                     ) ||                       
                                                 prefixMatched(number,                                     37                                     ) ||                       
                                                 prefixMatched(number,                                     6                                     )) &&                       
                                                 ((sumOfDoubleEvenPlace(number) +                       
                                                 sumOfOddPlace(number)) %                                     10                                     ==                                     0                                     );                       
                                                 }                       
           
                                                 // Get the result from Step 2                       
                                                 public                                     static                                     int                                     sumOfDoubleEvenPlace(                                     long                                     number)                       
                                                 {                       
                                                 int                                     sum =                                     0                                     ;                       
                                                 String num = number +                                     ""                                     ;                       
                                                 for                                     (                                     int                                     i = getSize(number) -                                     2                                     ; i >=                                     0                                     ; i -=                                     2                                     )                       
                                                 sum += getDigit(Integer.parseInt(num.charAt(i) +                                     ""                                     ) *                                     2                                     );                       
                                   
                                                 return                                     sum;                       
                                                 }                       
           
                                                 // Return this number if it is a single digit, otherwise,                       
                                                 // return the sum of the two digits                       
                                                 public                                     static                                     int                                     getDigit(                                     int                                     number)                       
                                                 {                       
                                                 if                                     (number <                                     9                                     )                       
                                                 return                                     number;                       
                                                 return                                     number /                                     10                                     + number %                                     10                                     ;                       
                                                 }                       
           
                                                 // Return sum of odd-place digits in number                       
                                                 public                                     static                                     int                                     sumOfOddPlace(                                     long                                     number)                       
                                                 {                       
                                                 int                                     sum =                                     0                                     ;                       
                                                 String num = number +                                     ""                                     ;                       
                                                 for                                     (                                     int                                     i = getSize(number) -                                     1                                     ; i >=                                     0                                     ; i -=                                     2                                     )                       
                                                 sum += Integer.parseInt(num.charAt(i) +                                     ""                                     );                       
                                                 return                                     sum;                       
                                                 }                       
           
                                                 // Return true if the digit d is a prefix for number                       
                                                 public                                     static                                     boolean                                     prefixMatched(                                     long                                     number,                                     int                                     d)                       
                                                 {                       
                                                 return                                     getPrefix(number, getSize(d)) == d;                       
                                                 }                       
           
                                                 // Return the number of digits in d                       
                                                 public                                     static                                     int                                     getSize(                                     long                                     d)                       
                                                 {                       
                                                 String num = d +                                     ""                                     ;                       
                                                 return                                     num.length();                       
                                                 }                       
           
                                                 // Return the first k number of digits from                       
                                                 // number. If the number of digits in number                       
                                                 // is less than k, return number.                       
                                                 public                                     static                                     long                                     getPrefix(                                     long                                     number,                                     int                                     k)                       
                                                 {                       
                                                 if                                     (getSize(number) > k) {                       
                                                 String num = number +                                     ""                                     ;                       
                                                 return                                     Long.parseLong(num.substring(                                     0                                     , k));                       
                                                 }                       
                                                 return                                     number;                       
                                                 }                       
                         }                       

C#

                         // C# program to check if a given                       
                         // credit card is valid or not.                       
                         using                                     System;                       
           
                         class                                     CreditCard {                       
                                   
                                                 // Main Method                       
                                                 public                                     static                                     void                                     Main()                       
                                                 {                       
                                                 long                                     number = 5196081888500645L;                       
                                                 Console.Write(number +                                     " is "                                     +                       
                                                 (isValid(number) ?                       
                                                 "valid"                                     :                                     "invalid"                                     ));                       
                                                 }                       
           
                                                 // Return true if the card number is valid                       
                                                 public                                     static                                     bool                                     isValid(                                     long                                     number)                       
                                                 {                       
                                                 return                                     (getSize(number) >= 13 &&                       
                                                 getSize(number) <= 16) &&                       
                                                 (prefixMatched(number, 4) ||                       
                                                 prefixMatched(number, 5) ||                       
                                                 prefixMatched(number, 37) ||                       
                                                 prefixMatched(number, 6)) &&                       
                                                 ((sumOfDoubleEvenPlace(number) +                       
                                                 sumOfOddPlace(number)) % 10 == 0);                       
                                                 }                       
           
                                                 // Get the result from Step 2                       
                                                 public                                     static                                     int                                     sumOfDoubleEvenPlace(                                     long                                     number)                       
                                                 {                       
                                                 int                                     sum = 0;                       
                                                 String num = number +                                     ""                                     ;                       
                                                 for                                     (                                     int                                     i = getSize(number) - 2; i >= 0; i -= 2)                       
                                                 sum += getDigit(                                     int                                     .Parse(num[i] +                                     ""                                     ) * 2);                       
                                   
                                                 return                                     sum;                       
                                                 }                       
           
                                                 // Return this number if it is a                       
                                                 // single digit, otherwise, return                       
                                                 // the sum of the two digits                       
                                                 public                                     static                                     int                                     getDigit(                                     int                                     number)                       
                                                 {                       
                                                 if                                     (number < 9)                       
                                                 return                                     number;                       
                                                 return                                     number / 10 + number % 10;                       
                                                 }                       
           
                                                 // Return sum of odd-place digits in number                       
                                                 public                                     static                                     int                                     sumOfOddPlace(                                     long                                     number)                       
                                                 {                       
                                                 int                                     sum = 0;                       
                                                 String num = number +                                     ""                                     ;                       
                                                 for                                     (                                     int                                     i = getSize(number) - 1; i >= 0; i -= 2)                       
                                                 sum +=                                     int                                     .Parse(num[i] +                                     ""                                     );                       
                                                 return                                     sum;                       
                                                 }                       
           
                                                 // Return true if the digit d                       
                                                 // is a prefix for number                       
                                                 public                                     static                                     bool                                     prefixMatched(                                     long                                     number,                                     int                                     d)                       
                                                 {                       
                                                 return                                     getPrefix(number, getSize(d)) == d;                       
                                                 }                       
           
                                                 // Return the number of digits in d                       
                                                 public                                     static                                     int                                     getSize(                                     long                                     d)                       
                                                 {                       
                                                 String num = d +                                     ""                                     ;                       
                                                 return                                     num.Length;                       
                                                 }                       
           
                                                 // Return the first k number of digits from                       
                                                 // number. If the number of digits in number                       
                                                 // is less than k, return number.                       
                                                 public                                     static                                     long                                     getPrefix(                                     long                                     number,                                     int                                     k)                       
                                                 {                       
                                                 if                                     (getSize(number) > k)                       
                                                 {                       
                                                 String num = number +                                     ""                                     ;                       
                                                 return                                     long                                     .Parse(num.Substring(0, k));                       
                                                 }                       
                                                 return                                     number;                       
                                                 }                       
                         }                       
           
                         // This code is contributed by nitin mittal.                       

输出：

5196081888500645 is valid

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