Cod sursa(job #3224562)

Utilizator Remus.RughinisRemus Rughinis Remus.Rughinis Data 15 aprilie 2024 17:10:26
Problema Sortare topologica Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.98 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <queue>
#define MAXN 50000
#define DEBUG 0

using namespace std;

int pre[MAXN];
vector<int> post[MAXN];

int main(){
  int n, m;

  ifstream fin ("sortaret.in");
  fin >> n >> m;
  for(int i = 0; i < m; i ++){
    int a, b;
    fin >> a >> b;
    a --;
    b --;

    pre[b] ++;
    post[a].push_back(b);
  }

  if(DEBUG){
    for(int i = 0; i < n; i ++){
      printf("%d: %d |", i + 1, pre[i]);
      for(int j = 0; j < (int)post[i].size(); j ++)
        printf("%d ", post[i][j] + 1);
      printf("\n");
    }
  }

  queue<int> cd;
  for(int i = 0; i < n; i ++)
    if(pre[i] == 0)
      cd.push(i);

  ofstream fout ("sortaret.out");
  while(!cd.empty()){
    int id = cd.front();
    cd.pop();
    fout << id + 1 << " ";

    for(int i = 0; i < (int)post[id].size(); i ++){
      int node = post[id][i];
      pre[node] --;
      if(pre[node] == 0)
        cd.push(node);
    }
  }
  fout.close();

  return 0;
}