Submission #576176

#	Time	Username	Problem	Language	Result	Execution time	Memory
576176		elazarkoren	Game (IOI14_game)	C++17	42 / 100	1089 ms	8288 KiB

game

#include "game.h"
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;

mt19937 rng(time(0));

struct Dsu {
    int n;
    vi par, sz;
    Dsu() {}
    Dsu(int n): n(n) {
        par.resize(n), sz.resize(n, 1);
        iota(all(par), 0);
    }
    int Find(int i) {
        return par[i] == i ? i : par[i] = Find(par[i]);
    }
    bool Union(int a, int b) {
        int pa = Find(a), pb = Find(b);
        if (pa == pb) return false;
        if (sz[pa] < sz[pb]) swap(pa, pb);
        par[pb] = pa;
        sz[pa] += sz[pb];
        return true;
    }
};

set<pii> edges;
set<pii> tree;
int n;

void initialize(int N) {
    n = N;
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            edges.insert({i, j});
        }
    }
    Dsu dsu(n);
    vii e(all(edges));
    shuffle(all(e), rng);
    for (pii p : e) {
        if (dsu.Union(p.x, p.y)) {
            tree.insert(p);
        }
    }
}

int hasEdge(int u, int v) {
    if (u > v) swap(u, v);
    if (!tree.count({u, v})) {
        edges.erase(edges.find({u, v}));
        return 0;
    }
    Dsu dsu(n);
    set<pii> next;
    vii e(all(edges));
    shuffle(all(e), rng);
    for (auto [a, b] : e) {
        if (a != u || b != v) {
            if (dsu.Union(a, b)) next.insert({a, b});
        }
    }
    if (dsu.sz[dsu.Find(0)] != n) return 1;
    edges.erase(edges.find({u, v}));
    tree = next;
    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 27 / 27
• Subtask 3: 0 / 58