Submission #798872

#	Time	Username	Problem	Language	Result	Execution time	Memory
798872		t6twotwo	Keys (IOI21_keys)	C++17	9 / 100	3064 ms	38772 KiB

keys

#include "keys.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
struct dsu {
    int n;
    vector<int> p, s;
    dsu(int n) : n(n), p(n), s(n, 1) {
        iota(p.begin(), p.end(), 0);
    }
    int find(int x) {
        return x == p[x] ? x : p[x] = find(p[x]);
    }
    int size(int x) {
        return s[find(x)];
    }
    bool same(int x, int y) {
        return find(x) == find(y);
    }
    bool unite(int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) {
            return 0;
        }
        if (s[x] > s[y]) {
            swap(x, y);
        }
        p[x] = y;
        s[y] += s[x];
        return 1;
    }
};
vector<int> find_reachable(vector<int> R, vector<int> U, vector<int> V, vector<int> C) {
    int N = R.size(), M = C.size();
    if (C == vector(M, 0)) {
        dsu uf(N);
        for (int i = 0; i < M; i++) {
            uf.unite(U[i], V[i]);
        }
        vector<int> p(N);
        for (int i = 0; i < N; i++) {
            if (R[i] == 0) {
                p[i] = uf.size(i);
            } else {
                p[i] = 1;
            }
        }
        int mn = *min_element(p.begin(), p.end());
        vector<int> ans(N);
        for (int i = 0; i < N; i++) {
            if (p[i] == mn) {
                ans[i] = 1;
            }
        }
        return ans;
    }
    vector<vector<pair<int, int>>> adj(N);
    for (int i = 0; i < M; i++) {
        adj[U[i]].emplace_back(V[i], C[i]);
        adj[V[i]].emplace_back(U[i], C[i]);
    }
    vector<int> p(N, N);
    auto bfs = [&](int s) {
        vector<bool> have(N), vis(N);
        vector<vector<int>> w(N);
        vector<int> q;
        vis[s] = 1;
        q.push_back(s);
        for (int i = 0; i < q.size(); i++) {
            int x = q[i];
            have[R[x]] = 1;
            for (int y : w[R[x]]) {
                if (!vis[y]) {
                    vis[y] = 1;
                    q.push_back(y);
                }
            }
            w[R[x]].clear();
            for (auto [y, z] : adj[x]) {
                if (vis[y]) {
                    continue;
                }
                if (have[z]) {
                    vis[y] = 1;
                    q.push_back(y);
                } else {
                    w[z].push_back(y);
                }
            }
        }
        for (int x : q) {
            p[x] = q.size();
        }
    };
    vector<vector<int>> f(N), g(N);
    for (int i = 0; i < N; i++) {
        for (auto [j, k] : adj[i]) {
            if (R[i] == k) {
                f[i].push_back(j);
                g[j].push_back(i);
            }
        }
    }
    vector<int> v;
    vector<bool> vis(N);
    auto dfs = [&](auto dfs, int x) -> void {
        vis[x] = 1;
        for (int y : f[x]) {
            if (!vis[y]) {
                dfs(dfs, y);
            }
        }
        v.push_back(x);
    };
    for (int i = 0; i < N; i++) {
        if (!vis[i]) {
            dfs(dfs, i);
        }
    }
    fill(vis.begin(), vis.end(), 0);
    vector<int> b(N), t(N);
    auto sfd = [&](auto sfd, int x, int z) -> void {
        vis[x] = 1;
        b[x] = z;
        for (int y : g[x]) {
            if (!vis[y]) {
                sfd(sfd, y, z);
            } else if (b[x] != b[y]) {
                t[b[y]] = 1;
            }
        }
    };
    for (int i = N - 1; i >= 0; i--) {
        if (!vis[v[i]]) {
            sfd(sfd, v[i], v[i]);
        }
    }
    for (int i = 0; i < N; i++) {
        if (b[i] == i && !t[i]) {
            bfs(i);
        }
    }
    int mn = *min_element(p.begin(), p.end());
    vector<int> ans(N);
    for (int i = 0; i < N; i++) {
        if (p[i] == mn) {
            ans[i] = 1;
        }
    }
    return ans;
}

Compilation message (stderr)

keys.cpp: In lambda function:
keys.cpp:70:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |         for (int i = 0; i < q.size(); i++) {
      |                         ~~^~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 30
• Subtask 5: 0 / 33