HDU--Wolf and Rabbit(GCD)

Problem 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

21 22 2

 

Sample Output

NOYES

 

问题分析：抽象为一个数学模型，判断m和n的最大公约数是否为1，若GCD(m,n)==1，则代表狼可以搜索所有的洞穴，没有安全洞穴；否则存在安全洞穴。

#include<iostream>using namespace std;int MyGCD(int num1,int num2){while(num1%num2!=0){int temp = num1%num2;num1 = num2;num2 = temp;}return num2;}int main(){int a,b;int n;cin>>n;while(n--){cin>>a>>b;if(MyGCD(a,b)==1){cout<<"NO"<<endl;}elsecout<<"YES"<<endl;}return 0;}