Submission #648217

#	Time	Username	Problem	Language	Result	Execution time	Memory
648217		dxz05	Werewolf (IOI18_werewolf)	C++14	100 / 100	958 ms	173748 KiB

werewolf

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

using namespace std;

struct ReachabilityTree {
    vector<int> p, sz;
    vector<vector<int>> g;
    int id;

    vector<int> tin, tout;
    int timer;

    ReachabilityTree(int n) {
        n++;

        int m = 2 * n + 10;

        id = n + 1;
        p.assign(m, 0);
        sz.assign(m, 1);
        g.resize(m);
        iota(p.begin(), p.end(), 0);

        tin.resize(m);
        tout.resize(m);
        timer = 0;
    }

    inline int find(int x) {
        return (x == p[x] ? x : p[x] = find(p[x]));
    }

    inline bool same(int x, int y) {
        return find(x) == find(y);
    }

    inline bool unite(int x, int y) {
        if (same(x, y)) return false;
        x = find(x);
        y = find(y);
        if (sz[x] > sz[y]) swap(x, y);

        p[x] = id;
        p[y] = id;
        sz[id] += sz[x] + sz[y];
        g[id].push_back(x);
        g[id].push_back(y);

        id++;

        return true;
    }

    void dfs(int v){
        tin[v] = tout[v] = timer++;
        for (int u : g[v]){
            dfs(u);
            tout[v] = tout[u];
        }
    }

    void run_dfs(){
        for (int i = 0; i < g.size(); i++){
            if (find(i) == i) dfs(i);
        }
    }

};

struct Fenwick_Tree{
    vector<int> f;
    Fenwick_Tree(int n){
        f.resize(n + 2);
    }

    void add(int i, int val){
        i++;
        while (i < (int)f.size()){
            f[i] += val;
            i += -i & i;
        }
    }

    int get(int i){
        i++;
        int res = 0;
        while (i > 0){
            res += f[i];
            i -= -i & i;
        }
        return res;
    }

    int get(int l, int r){
        return get(r) - get(l - 1);
    }
};


vector<int> check_validity(int N, vector<int> X, vector<int> Y, vector<int> S, vector<int> E, vector<int> L, vector<int> R) {
    int M = X.size(), Q = S.size();

    vector<vector<int>> g(N);
    for (int i = 0; i < M; i++){
        g[X[i]].push_back(Y[i]);
        g[Y[i]].push_back(X[i]);
    }

    vector<vector<int>> q1(N), q2(N);
    vector<int> r1(Q), r2(Q);
    for (int i = 0; i < Q; i++){
        q1[L[i]].push_back(i);
        q2[R[i]].push_back(i);
    }

    ReachabilityTree t1(N), t2(N);
    for (int i = N - 1; i >= 0; i--){
        for (int j : g[i]){
            if (j > i) t1.unite(i, j);
        }

        for (int j : q1[i]){
            r1[j] = t1.find(S[j]);
        }
    }

    for (int i = 0; i < N; i++){
        for (int j : g[i]){
            if (j < i) t2.unite(i, j);
        }

        for (int j : q2[i]){
            r2[j] = t2.find(E[j]);
        }
    }

    t1.run_dfs();
    t2.run_dfs();

    int m = 2 * N + 10;

    vector<vector<int>> points(m);
    for (int i = 0; i < N; i++){
        int x = t1.tin[i], y = t2.tin[i];
        points[x].push_back(y);
    }

    vector<vector<pair<int, int>>> queries(m);
    for (int i = 0; i < Q; i++){
        int x1 = t1.tin[r1[i]], x2 = t1.tout[r1[i]];
        int y1 = t2.tin[r2[i]], y2 = t2.tout[r2[i]];

        if (x1 > 0) queries[x1 - 1].emplace_back(y1, y2);
        queries[x2].emplace_back(y1, y2);
    }

    Fenwick_Tree f(m);

    vector<map<pair<int, int>, int>> mp(m);
    for (int x = 0; x < m; x++){
        for (int y : points[x]) f.add(y, 1);

        for (auto now : queries[x]){
            int y1 = now.first, y2 = now.second;
            mp[x][make_pair(y1, y2)] = f.get(y1, y2);
        }
    }

    vector<int> ans(Q, 0);
    for (int i = 0; i < Q; i++){
        int x1 = t1.tin[r1[i]], x2 = t1.tout[r1[i]];
        int y1 = t2.tin[r2[i]], y2 = t2.tout[r2[i]];

        int inside = mp[x2][make_pair(y1, y2)];
        if (x1 > 0) inside -= mp[x1 - 1][make_pair(y1, y2)];

        ans[i] = (inside > 0);
    }

    return ans;
}

Compilation message (stderr)

werewolf.cpp: In member function 'void ReachabilityTree::run_dfs()':
werewolf.cpp:64:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |         for (int i = 0; i < g.size(); i++){
      |                         ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 8 / 8
• Subtask 3: 34 / 34
• Subtask 4: 51 / 51