POJ 1246 Find The Multiple

传送门：http://poj.org/problem?id=1426

Find The Multiple

Time Limit: 1000MS		Memory Limit: 10000K
Total Submissions: 28464		Accepted: 11802		Special Judge

Description

Given a positive integer n, write a program to find out a nonzero multiple m of n whose decimal representation contains only the digits 0 and 1. You may assume that n is not greater than 200 and there is a corresponding m containing no more than 100 decimal digits.

Input

The input file may contain multiple test cases. Each line contains a value of n (1 <= n <= 200). A line containing a zero terminates the input.

Output

For each value of n in the input print a line containing the corresponding value of m. The decimal representation of m must not contain more than 100 digits. If there are multiple solutions for a given value of n, any one of them is acceptable.

Sample Input

2
6
19
0

Sample Output

10
100100100100100100
111111111111111111

刚刚一开始，看到这么大数，被吓到了，想肯定是大数方面的知识，最后看了一下他们的题解，long long 能提交，但是因为边界的问题，总是错，最后看了一下他们的解题报告

#include <iostream>
using namespace std;

bool found;

void dfs(long long i,int n,int k){
    if(found)
        return ;
    if(k==19)
        return ;
    if(i%n==0){
        cout<<i<<endl;
        found=true;
    }

    dfs(i*10,n,k+1);
    dfs(i*10+1,n,k+1);

}

int main(){

    int n;
    while(cin>>n&&n!=0){
        found=false;
        dfs(1,n,0);
    }

}