Codeforces Round #158 (Div. 2) A - Adding Digits

Topic: http://codeforces.com/contest/260/problem/A

Ideas: a% b == 0 => a * 10 ^ n% b == 0

This problem initially ignored the sentence   If there are multiple possible answers, print any of them.

Like a long time I think the answer is more than one ah

Then see n ranges to know that this problem can not be considered a bit

#include <iostream>
#include <cstdlib>
using namespace std;

int a,b,n;
int main()
{
    cin >> a>>b>>n;
    a*=10;
    int flag=0;
    for(int i=0;i<10;i++)
    {
        if(a%b==0) 
        {
            flag=1;    
            break;
        }
        a++;
    }
    if(flag)
    {
        cout << a;
        for(int i=0;i<n-1;i++)
        {
            cout<<"0";
        }
        cout << endl;
    }
    else
    {
        cout << "-1"<<endl;
    }
return 0;
}

 

Reproduced in: https: //www.cnblogs.com/danielqiu/archive/2013/01/16/2863078.html