题解 | 记数问题

#include <stdio.h>

int main() {
    int n, t;
    scanf("%d %d", &n, &t);

    int sum = 0;
    for (int i = 1; i <= n; i++){
        int shu = i;
        while (shu) {
            if (shu % 10 == t){
                sum++;
            }
            shu /= 10;
        }
    }
    printf("%d", sum);
    return 0;
}