Cod sursa(job #2141499)

Utilizator jeanFMI - Petcu Ion Cristian jean Data 24 februarie 2018 13:06:49
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include<iostream>
#include<algorithm>
#include<vector>
#include<utility>
#include<unordered_set>
#include<unordered_map>
#include<cmath>
using namespace std;

typedef unordered_map< int, vector<int> > Graph;
typedef unordered_set<int> uset;

void top_sort_inner(Graph &G, int node, uset &used, vector<int> &sol) {
    if (used.find(node) != used.end()) {
        return;
    }

    used.insert(node);
    for (auto &v : G[node]) {
        top_sort_inner(G, v, used, sol);
    }
    sol.push_back(node);
}

vector<int> top_sort(Graph &G) {
    uset used;
    vector<int> sol;
    for (auto it = G.begin(); it != G.end(); it++) {
        top_sort_inner(G, it->first, used, sol);
    }
    reverse(sol.begin(), sol.end());
    return sol;
}


int main() {
    freopen("sortaret.in", "r", stdin);
    freopen("sortaret.out", "w", stdout);

    int N, M, x, y;
    cin >> N >> M;

    Graph G;
    for (int i = 0 ; i < N; i++) {
        G[i + 1] = vector<int>();
    }

    for (int i = 0 ; i < M ; i++) {
        cin >> x >> y;
        G[x].push_back(y);
    }

    vector<int> sol = top_sort(G);
    for (auto &v : sol) {
        cout << v << ' ';
    }

    return 0;
}