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);
}
 
ll e(ll x) {
    return x*(x+1)/2;
}
 
int main() {
 
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
 
 
    cin >> n;
 
    ll ans = 0;
    while (n > 0) {
        ll x = -1;
        for (ll b = 1e9; b >= 1; b /= 2) {
            while (ok(x+b)) x += b;
        }
        n -= e(x)+1;
        ans++;
    }
 
    cout << ans << "\n";
 
 
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED

Test 4

Verdict: WRONG ANSWER

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: ACCEPTED

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER