Equilateral numbers

#include<bits/stdc++.h>
using namespace std;
using ll = long long;

ll n;

bool ok(ll x) {
    ll e = x*(x+1)/2;
    return (e <= n);
}

int main() {

    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);

    cin >> n;

    int ans = 0;
    while (n > 0) {
        ll x = -1;
        for (ll b = 1e6; b >= 1; b /= 2) {
            while (ok(x+b)) x += b;
        }
        n -= x;
        ans++;
    }

    cout << ans << "\n";


}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: ACCEPTED

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER