NYoj410how many ones?(同余定理）

how many ones?

时间限制：3000 ms  |  内存限制：65535 KB

难度：2

描述

Given any integer 0 <= n <= 10000 not divisible by 2 or 5, some multiple of n is a number which in decimal notation is a sequence of 1's. How many digits are in the smallest such a multiple of n?

输入

Each line contains a number n.

输出

Output the number of digits.

样例输入

3 7 9901

样例输出

3612

#include<stdio.h>//AC代码int main(){int n;while(~scanf("%d",&n)){int i,sum=0;for( i=1;;i++){sum=(sum*10+1)%n;if(!sum)break;}printf("%d\n",i);}return 0;}