Submission #1207075

#	Time	Username	Problem	Language	Result	Execution time	Memory
1207075		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 collisions(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 = 5473;

int hack() {
    ll cols = 0;
    vector<ll> A(bs);
    while (cols == 0) {
        for (int i = 0; i < bs; ++i) A[i] = rnd() % (ll) (1e10) + 29638;
        cols = collisions(A);
    }
    int Rpos = 0;
    for (int delta = (1 << 12); 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 << 12); 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 main() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    cin >> N;
    cout << hack() << "\n" << SUM;
}

Compilation message (stderr)

hack.cpp: In function 'int main()':
hack.cpp:98:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
hack.cpp:99:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccLZEblV.o: in function `collisions(std::vector<long long, std::allocator<long long> >)':
grader.cpp:(.text+0x470): multiple definition of `collisions(std::vector<long long, std::allocator<long long> >)'; /tmp/cck9hkrH.o:hack.cpp:(.text+0x1d0): first defined here
/usr/bin/ld: /tmp/ccLZEblV.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cck9hkrH.o:hack.cpp:(.text.startup+0x20): first defined here
collect2: error: ld returned 1 exit status