1048 数字加密 (20 分)

#include <stdio.h>

#include <string.h>

int main()

{

    char A[101], B[101];
    char encrypt[] = "0123456789JQK";
    
    scanf("%s %s", A, B);
    
    int lenA = strlen(A);
    int lenB = strlen(B);

    int maxlen = lenA > lenB ? lenA : lenB;
    int a, b;



    for(int i = 0; i < maxlen; i++)

    {

        a = lenA + i - maxlen < 0 ? 0 : A[lenA + i - maxlen] - '0';

        b = lenB + i - maxlen < 0 ? 0 : B[lenB + i - maxlen] - '0';

        if((maxlen - i) % 2)    putchar(encrypt[(a + b) % 13]);

        else                    putchar('0' + (b - a < 0 ? b - a + 10 : b - a));

    }

 

    return 0;

}