PKU OJ - 1426 Find The Multiple

In PKU OJ,use G++ will AC, but use C++ will  TLE.
I think I should prune some useless branches.
在PKU 用 G++可以AC過，用C++會TLE 
可能要用點剪枝，還在努力中讓兩個都過...

The following program is my ACcepted code for PKU OJ 1426 Find The Multiple (only in G++).
It's a for everybody to learn and discuss.
If there is any mistake or comment, please let me know.  :D

此乃PKU 1426 的AC code! (只有在G++)
歡迎一同討論學習，如有錯誤與任何建議請留言 : )

點這裡看題目 Click here to see this Problem!

//This program is for PKU OJ 1426 Find The Multiple
//http://poj.org/problem?id=1426

#include<stdio .h="">
#include<iostream>
#include<queue>
using namespace std;

long long int BFS(int n)//Breadth First Search
{
    long long int ans;
    queue<long int="" long=""> q;
 
    while(!q.empty())//clear the queue
        q.pop();
 
    q.push(1);
 
    while(1)//use while(!q.empty()) will get WA.... = = and I don't know why.
    {
        ans = q.front();//access the "oldest" element in the queue
        q.pop();//pop the above "oldest" element in the queue
     
        if(ans % n == 0)
            return ans;
     
        q.push(10 * ans);
        q.push(10 * ans + 1);
    }
}

int main()
{
    int n;

    while(scanf("%d", &amp;n)!=EOF)
    {
        if( n == 0)
            break;

        printf("%lld\n", BFS(n));
    }
    return 0;
}

Please feel free to use it after adding this blog as an reference. (http://autekroy.blogspot.tw) If there is any mistake or comment, please let me know. :D 

歡迎使用與分享任何內容，但請記得標示此部落格為出處。(http://autekroy.blogspot.tw/) 如果有發現任何的錯誤與建議請留言或跟我連絡。 : )