497 | Лентяй

C++ Solution:

#include <iostream>
using namespace std;

int mas[35] = {0};

int main{
  int t,i,j,n,r,a,b,f;
  cin >> t;
  for (i = 0 ; i < t ; i++)
  {
    cin >> n;
    for (j = 0 ; j < 35 ; j++) mas[j] = 0;
    for (j = 0 ; j < n ; j++)
    {
      cin >> a >> b;
      for (r = a ; r <= b ; r++) mas[r]++;
    }
    f = 0;
    for (r = 0 ; r < 35 ; r++){
      if (mas[r] == n){ f = 1; break; }
    }
    if (f == 1) cout << "YES" << endl;
    else cout << "NO" << endl;
  }
  return 0;
}