View Code of Problem 6

#include<stdio.h>
int main(){
	int t,n,Dan,len,A[100][2]={0},i;
	scanf("%d",&t);
	while(t){
		Dan=0;
		scanf("%d",&n);
		for(int j=0;j<n;j++){
			scanf("%d %d",&A[j][0],&A[j][1]);
		}
		len = A[0][1]-A[0][0];
		Dan=A[0][1];
		for( i=1;i<n;i++){
			Dan+=len;
			if(i<=n-2){
				if((Dan<A[i][1]&&Dan>A[i][0])||(Dan>A[i+1][0])){
					printf("NO");
					break;
			    }
			}
			if(i==n-1){
				if(Dan<A[i][1]&&Dan>A[i][0]){
					printf("NO");
					break;
				}
			}
		}
		if(i==n){
			printf("YES");
		}
			t--;
	}
	return 0;
}