View Code of Problem 6

#include<stdio.h>
int main()
{
	int i,j,k;
	int t,n,m;
	int l[50001],r[50001],flag[100];
	scanf("%d",&t);
	for ( k =0; k < t; k++)
	{
		flag[t] = 1;
		scanf("%d",&n);
		for ( i = 0; i < n; i++)
			scanf("%d%d",&l[i],&r[i]);
		for ( i = r[0]; i <= l[1]; i++)
		{
			m = i - l[0];
			for ( j = 1; j < n; j++)
				if ( r[j] - l[j] > m )
					flag[k] = 0;
		}
	}
	for ( k =0; k < t; k++)
	{
		if ( flag[k] )
			printf("YES\n");
		else 
			printf("NO\n");
	}
	return 0;
}