Submission #1207067

#	Time	Username	Problem	Language	Result	Execution time	Memory
1207067		alterio	Hack (APIO25_hack)	C++20	25 / 100	1484 ms	16456 KiB

hack

#include "hack.h"
#include <bits/stdc++.h>

using namespace std;

#define ll long long

ll C(ll x) {
    return (x * (x + 1)) / 2;
}

int hack() {
    vector<ll> x;
    for (int i = 1; i <= 1e6; i++) x.push_back(i);
    ll get = collisions(x);
    for (ll sz = 2; sz <= 1e6; sz++) {
        ll l = 0, r = 1e6 + 1;
        while (l + 1 < r) {
            ll mid = (l + r) / 2;
            if (sz * C(mid) <= get) l = mid;
            else r = mid;
        }
        ll rest = get - sz * C(l);
        if (rest % (l + 1) != 0) continue;
        ll sum = sz * (l + 1) + rest / (l + 1);
        if (sum == 1e6) return sz;
    }
}

Compilation message (stderr)

hack.cpp: In function 'int hack()':
hack.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type]
   28 | }
      | ^

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 0 / 75