G - 数论，最大公约数
Time Limit:1000MS Memory Limit:32768KB 64bit IO Format:%I64d & %I64u
Description
There is a hill with n holes around. The holes are signed from 0 to n-1. 
A rabbit must hide in one of the holes. A wolf searches the rabbit in anticlockwise order. The first hole he get into is the one signed with 0. Then he will get into the hole every m holes. For example, m=2 and n=6, the wolf will get into the holes which are signed 0,2,4,0. If the rabbit hides in the hole which signed 1,3 or 5, she will survive. So we call these holes the safe holes.
Input
The input starts with a positive integer P which indicates the number of test cases. Then on the following P lines,each line consists 2 positive integer m and n(0<m,n<2147483648).
Output
For each input m n, if safe holes exist, you should output "YES", else output "NO" in a single line.
Sample Input
2
1 2
2 2
Sample Output
NO
YES
题解：只要m，n的最大公约数为1，就没有输出NO，否则输出YES
#include<iostream>
using namespace std;
int gcd(int a,int b)
{
return b==?a:gcd(b,a%b);
}
int main()
{
int t,m,n;
cin>>t;
while(t--)
{
cin>>m>>n;
if(gcd(m,n)==)
cout<<"NO"<<endl;
else
cout<<"YES"<<endl;
}
}