Cod sursa(job #2786201)

Utilizator lucamLuca Mazilescu lucam Data 20 octombrie 2021 15:23:44
Problema Sortare topologica Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <bits/stdc++.h>

std::ifstream in("sortaret.in");
std::ofstream out("sortaret.out");

constexpr int N = 5e4 + 1, M = 1e5 + 1;
std::vector<int> g[N];

// int pred[N];

// void bfs(std::queue<int> &q) {
//     while (!q.empty()) {
//         int u = q.front();
//         q.pop();
//         out << u << ' ';
//         for (auto v : g[u]) {
//             --pred[v];
//             if (pred[v] == 0) {
//                 q.push(v);
//             }
//         }
//     }
// }

std::bitset<N> vis;
int res[N];
int res_idx = 0;

void dfs(int u) {
    vis[u] = true;
    for (auto v : g[u]) {
        if (vis[v]) {
            continue;
        }
        dfs(v);
    }
    res[res_idx++] = u;
}

int main() {
    int n, m;
    in >> n >> m;
    for (int i = 0; i < m; ++i) {
        int u, v;
        in >> u >> v;
        g[u].push_back(v);
        // ++pred[v];
    }
    std::queue<int> q;
    for (int i = 1; i <= n; ++i) {
        if (vis[i])
            continue;
        dfs(i);
    }
    for (int i = res_idx - 1; i >= 0; --i) {
        out << res[i] << ' ';
    }
    out << '\n';
    // bfs(q);
}