num函数用递归实现，获取每次需要加的数 用for循环实现加n次 count做计数器
#include <stdio.h>

int num(int a,int res, int t) {
    if (t == 1) {return res;}
    res = res * 10 + a;
    return num(a, res, t-1);
}

int main() {
    int a = 0,n = 0,count = 0;
    scanf("%d",&a);
    scanf("%d",&n);
    for (int i = 1; i <= n; i++) {
        count += num(a,a, i);
    }
    printf("%d\n",count);
    return 0;
}