Submission #423354

#	Time	Username	Problem	Language	Result	Execution time	Memory
423354		timmyfeng	Toy Train (IOI17_train)	C++17	100 / 100	605 ms	1648 KiB

train

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

const int N = 5000;

vector<int> to[N], from[N], a;
int degree[N], n, m;

void bfs(vector<int> &visited, int player) {
    queue<int> que;
    for (int i = 0; i < n; ++i) {
        degree[i] = 0;
        if (visited[i] == 1) {
            que.push(i);
        }
    }

    while (!que.empty()) {
        int u = que.front();
        que.pop();
        for (auto c : from[u]) {
            if (visited[c] == 0) {
                if (a[c] == player || ++degree[c] == (int) to[c].size()) {
                    visited[c] = 1;
                    que.push(c);
                }
            }
        }
    }
}

vector<int> who_wins(vector<int> a, vector<int> r, vector<int> u, vector<int> v) {
    n = a.size(), m = u.size(), ::a = a;

    for (int i = 0; i < m; ++i) {
        to[u[i]].push_back(v[i]);
        from[v[i]].push_back(u[i]);
    }

    bool loop = true;
    while (loop) {
        loop = false;
        vector<int> visited = r;
        bfs(visited, 1);
        for (auto &i : visited) {
            i = 1 - i;
        }

        bfs(visited, 0);
        for (int i = 0; i < n; ++i) {
            if (visited[i] == 1 && r[i] == 1) {
                loop = true;
                r[i] = 0;
            }
        }
    }

    vector<int> ans = r;
    bfs(ans, 1);
    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51