View Code of Problem 6

#include<stdio.h>
#include<string.h>
int main(){ 
    int i,j,k,t,n,max,s[50000][2],flag;
    scanf("%d",&t);
    for(i=0;i<t;i++){
    	scanf("%d",&n);
    	max=0;
    	for(j=0;j<n;j++){
    		scanf("%d%d",&s[j][0],&s[j][1]);
    		if(s[j][1]-s[j][0]>max)
    		   max=s[j][1]-s[j][0];
		}
		flag=0;
		for(k=0;k<n-1;k++){
			if(max+s[k][0]<s[k+1][1]&&max+s[k][0]>s[k+1][0]) flag=1;	
			else if(max+s[k][0]>s[k+1][1]) flag=1;
		}
		if(flag==1) printf("NO\n");
		else printf("YES\n");
	}
	return 0;
}