UVA 10127 - Ones

题目链接

题意：求出多少个1组成的数字能整除n
思路：一位位去取模，记录答案即可
代码：

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

int n;

int main() {
    while (~scanf("%d", &n)) {
    int ans = 1;
    int now = 1;
    while (now) {
        now = (now * 10 + 1) % n;
        ans++;
    }
    printf("%d\n", ans);
    }
    return 0;
}