The HELL?
Difference between en2 and en3, changed 0 character(s)
Run this `O(n^2)` program in CF custom test↵

~~~~~↵
#include "bits/stdc++.h"↵
using namespace std;↵

long long n;↵

int main() {↵
    cin >> n;↵
    for(long long i = 1; i <= n; i++) {↵
        for(long long j = 1; j <= n; j++) {↵
            if((i ^ j) == 0) {↵
                if(i != j) {↵
                    cout << "NO!\n";↵
                    return 0;↵
                }↵
            }↵
        }↵
    }↵
    cout << "YES\n";↵
}↵
~~~~~↵

with `n = 100000000000`↵

You would expect it to be much longer than 1 second, but it takes↵

`15 ms`↵

[screenshot](https://imgur.com/a/OTNWR9I)

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en3 English Qualified 2020-07-09 19:59:59 0 (published)
en2 English Qualified 2020-07-09 19:57:46 9 Tiny change: '00000`\n\nYou woul' -> '00000`\n\n`O(n^2)`\nYou woul' (saved to drafts)
en1 English Qualified 2020-07-09 19:56:00 600 Initial revision (published)