题解 | #[NOIP2008]ISBN号码#

#include <stdio.h>
#include<malloc.h>
#include<string.h>

int main() {
   char str[13];
    scanf("%s", str);

    int sum = 0;
    for (int i = 0, j = 1; i < 11; i++) {
        if (str[i] >= '0' && str[i] <= '9') { //是数字
            sum += ( str[i] - '0') * j;
            j++;
        }

    }
    if (sum % 11 == str[12] - '0' || (sum % 11 == 10 && str[12] == 'X'))
        printf("Right\n");
    else {
        if (sum%11 == 10) {   //如果余数为10，则识别码为大写字母X
            for (int i = 0; i < 12; i++) {
                printf("%c", str[i]);

            }
            printf("X");

        } else {
            for (int i = 0; i < 12; i++) {
                printf("%c", str[i]);
            }
            printf("%d", sum % 11);
        }
    }
}