Submission #1207078

#	Time	Username	Problem	Language	Result	Execution time	Memory
1207078		friendiks	Hack (APIO25_hack)	C++20	Compilation error	0 ms	0 KiB

hack

#ifndef LOCAL
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC diagnostic ignored "-Wpedantic"
#endif

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

auto seed = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937_64 rnd(1488);
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename V>
using table = gp_hash_table<T, V>;

using i128 = __int128;
using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;

const ll INF = 2e18;
const int inf = 2e9;
const int maxn = 1e5;
const int MOD = 988244353;
const ld pi = acos(-1);
const int P = 5167;
const int L = 26;
const ld EPS = 1e-7;

template<typename T, typename V>
void fill(T &container, V value) {
    for (auto &c: container)
        c = value;
}

int N;
int SUM = 0;

ll collision1s(std::vector<long long> x) {
    SUM += x.size();
    map<ll, ll> mp;
    for (auto c: x) mp[c % N]++;
    ll ans = 0;
    for (auto [a, b]: mp) ans += b * (b - 1) / 2;
    return ans;
}

int bs = 64000;

int hack() {
    ll cols = 0;
    vector<ll> A(bs);
    while (cols == 0) {
        map<ll, int> mp;
        for (int i = 0; i < bs; ++i) {
            while (mp[A[i]] > 0)
                A[i] = rnd() % (ll) (1e10) + 29638;
            mp[A[i]]++;
        }
        cols = collisions(A);
    }
    int Rpos = 0;
    for (int delta = (1 << 29); delta > 0; delta /= 2) {
        if (Rpos + delta > bs) continue;
        vector<ll> v;
        for (int i = 0; i < Rpos + delta; ++i) {
            v.push_back(A[i]);
        }
        if (collisions(v) == 0) Rpos += delta;
    }
    int Lpos = Rpos;
    for (int delta = (1 << 29); delta > 0; delta /= 2) {
        if (Lpos - delta < 0) continue;
        vector<ll> v;
        for (int i = Lpos - delta + 1; i <= Rpos; ++i) {
            v.push_back(A[i]);
        }
        if (collisions(v) == 0) Lpos -= delta;
    }
    ll k = abs(A[Lpos] - A[Rpos]);
    ll ans = INF;
    for (ll d1 = 1; d1 * d1 <= k; ++d1) {
        if (k % d1 == 0) {
            ll d2 = k / d1;
            if (collisions({1, 1 + d1})) {
                ans = min(ans, d1);
            }
            if (collisions({1, 1 + d2})) {
                ans = min(ans, d2);
            }
        }
    }
    return ans;
}

int main1() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    int t;
    cin >> t;
    int mx = 0;
    while (t--) {
        SUM = 0;
        cin >> N;
        cout << hack() << "\n";
        mx = max(mx, SUM);
    }
    cout << mx;
}

Compilation message (stderr)

hack.cpp: In function 'int hack()':
hack.cpp:66:16: error: 'collisions' was not declared in this scope; did you mean 'collision1s'?
   66 |         cols = collisions(A);
      |                ^~~~~~~~~~
      |                collision1s
hack.cpp:75:13: error: 'collisions' was not declared in this scope; did you mean 'collision1s'?
   75 |         if (collisions(v) == 0) Rpos += delta;
      |             ^~~~~~~~~~
      |             collision1s
hack.cpp:84:13: error: 'collisions' was not declared in this scope; did you mean 'collision1s'?
   84 |         if (collisions(v) == 0) Lpos -= delta;
      |             ^~~~~~~~~~
      |             collision1s
hack.cpp:91:17: error: 'collisions' was not declared in this scope; did you mean 'collision1s'?
   91 |             if (collisions({1, 1 + d1})) {
      |                 ^~~~~~~~~~
      |                 collision1s
hack.cpp:94:17: error: 'collisions' was not declared in this scope; did you mean 'collision1s'?
   94 |             if (collisions({1, 1 + d2})) {
      |                 ^~~~~~~~~~
      |                 collision1s
hack.cpp: In function 'int main1()':
hack.cpp:115:1: warning: no return statement in function returning non-void [-Wreturn-type]
  115 | }
      | ^
hack.cpp:103:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
hack.cpp:104:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~