View Code of Problem 131

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cctype>
#include<vector>
#include<cmath>
using namespace std;
int main(void){
	int a,b;
	while(cin>>a>>b){
		int arr[a+1][a+1]{0};
		for(int i=0;i<b;i++){
			int t1,t2;
			cin>>t1>>t2;
			arr[t1][t2]=1;
		}
		for(int i=1;i<=a;i++){
			for(int j=1;j<=a;j++){
				for(int k=1;k<=a;k++){
					if(arr[j][i]&&arr[i][k]){
						arr[j][k]=1;
					}
				}
			}
		}
		int flag=1;
		for(int i=1;i<=a;i++)
			for(int j=1;j<=a;j++)
				if(arr[i][j]&&arr[j][i])
					flag=0;
					
		if(flag) 
			cout<<"RIGHT"<<endl;
        else 
			cout<<"ERROR"<<endl;
	}
}