View Code of Problem 6

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scanner=new Scanner(System.in);
		int t=scanner.nextInt();
		while(t-->0) {
			String ans="YES";
			int n=scanner.nextInt();
			int[][] trap=new int[n][2];
			int dis=0;
			for(int i=0;i<n;i++) {
				trap[i][0]=scanner.nextInt();
				trap[i][1]=scanner.nextInt();
				if(dis<trap[i][1]-trap[i][0]) {
					dis=trap[i][1]-trap[i][0];
				}
			}
			for(int i=0;i<n-1;i++) {
				if(trap[i][0]+dis>trap[i+1][0]) {
					ans="NO";
					break;
				}
			}
			System.out.println(ans);
		}
	}

}