제출 #1248636

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1248636		countless	늑대인간 (IOI18_werewolf)	C++20	0 / 100	3504 ms	23444 KiB

werewolf

#include "werewolf.h"
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

#define sp <<" "<<
#define endl "\n"

// as human, we can only reach other nodes such that the next node is either:
// - less than the current node
// - below Ri

// as wolf:
// - greater than the current node
// - above Li

// so every time in a path and we go leq or greq
// we can find bounds L R that allow this edge.
// generalize: there are edges that only certain bounds can take
// how do we query these edges and connectivity quickly?

// instead phrase it from one side
// only consider human
// process in increasing Ri

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 Q = S.size(), M = X.size();
    vector<int> ans(Q);

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

    for (int i = 0; i < Q; i++) {
        if (S[i] < L[i] or E[i] > R[i]) {
            ans[i] = 0;
            continue;
        }

        // bfs
        vector<int> bs;
        vector<bool> vis;

        vis.assign(N, false);
        queue<int> q;
        vis[S[i]] = true;
        q.emplace(S[i]);
        while (!q.empty()) {
            auto u = q.front(); q.pop();
            for (auto &v : adj[u]) {
                if (!vis[v] and v >= L[i]) {
                    vis[v] = true;
                    q.emplace(v);

                    if (L[i] <= v and v <= R[i]) {
                        bs.emplace_back(v);
                    }
                }
            }
        }

        vis.assign(N, false);
        for (auto &v : bs) {
            vis[v] = true;
            q.emplace(v);
        }

        while (!q.empty()) {
            auto u = q.front(); q.pop();

            for (auto &v : adj[u]) {
                if (!vis[v] and v <= R[i]) {
                    vis[v] = true;
                    q.emplace(v);
                }
            }
        }

        // for (int i = 0; i < N; i++) {
        //     cerr << vis[i] << " ";
        // }   cerr << endl;

        ans[i] = vis[E[i]];
    }

    return ans;
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 8
• Subtask 3: 0 / 34
• Subtask 4: 0 / 51