View Code of Problem 6

#include <stdio.h>
void main(){
	int T;
	scanf("%d",&T);
	while(T--){
		int n,k,step=0;
		scanf("%d",&n);
		int a[2*n],i=0;
		k=n;
		while(k--){
			scanf("%d %d",&a[i],&a[i+1]);
			if(a[i+1]-a[i]>step) step=a[i+1]-a[i];
			i=i+2;
		}
		for(i=0;i<=2*n-2;i=i+2){
			if((i+2)<2*n&&a[i]+step>a[i+1]){
				printf("NO\n");
				break;
			}
			if((i+2)<2*n&&a[i+1]!=a[i+2]){
				if(a[i+1]+step>a[i+2]){
					printf("NO\n");
				    break;
				}
			}
		}
		if(i>2*n-2) printf("YES\n");
	}
}