View Code of Problem 6

#include <stdio.h>
int main(){
  int T;
  scanf("%d", &T);
  while(T--){
    int n;
    int a[100], b[100];
    scanf("%d", &n);
    for(int j = 0; j < n; j++)
      scanf("%d%d", &a[j], &b[j]);
  int step = b[0];
    while(step <= a[1]){
      int flag = 1, i = step, j;
      for(j = 1; j < n - 1; j++){
        i += step;
        if(i < b[j] || i > a[j + 1]){
          flag = 0;
          break;
        }  }
      if(i + step < b[j])
        flag = 0;
      if(flag){
        printf("YES\n");
        break;            }
      else                step++;
    }
    if(step > a[1])
      printf("NO\n");
  }
  return 0;
}