题目地址http://codeforces.com/problemset/problem/584/A
A. Olesya and Rodion
time limit per test1 second
memory limit per test256 megabytes
inputstandard input
outputstandard output
Olesya loves numbers consisting of n digits, and Rodion only likes numbers that are divisible by t. Find some number that satisfies both of them.
Your task is: given the n and t print an integer strictly larger than zero consisting of n digits that is divisible by t. If such number doesn’t exist, print - 1.
Input
The single line contains two numbers, n and t (1 ≤ n ≤ 100, 2 ≤ t ≤ 10) — the length of the number and the number it should be divisible by.
Output
Print one such positive number without leading zeroes, — the answer to the problem, or - 1, if such number doesn’t exist. If there are multiple possible answers, you are allowed to print any of them.
Examples
inputCopy
3 2
outputCopy
712
题目翻译:A喜欢N位数,B喜欢能被T整除的数字,求满足两个条件的数字,情况很多随便写,不存在就输出-1.
#include<iostream>
using namespace std;
int main()
{
int n,t;
cin >> n >> t;
if(t!=10)
{
for(int i = 0;i<n;i++)cout<< t;
cout<<endl;
}
else
{
if(n == 1)cout<<-1<<endl;
else
{
for(int i = 0;i<n-1;i++)cout<< 1;
cout<<0<<endl;
}
}
return 0;
}