Cod sursa(job #769062)

Utilizator ioana26Ioana Andronescu ioana26 Data 18 iulie 2012 10:45:06
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
/*
Sortarea topologica.
*/

#include <iostream>
#include <vector>
#include <stack>
#include <stdio.h>
#include <stdbool.h>

#define MAXN	100050
#define ALB		0
#define NEGRU	1

using namespace std;

int nr_noduri, nr_muchii, nr_comp_conexe;
bool vizitat[MAXN];
vector<int> noduri[MAXN];
stack<int> stiva;

void dfs (int u) {
	vizitat[u] = NEGRU;
	int i;
	for (i = 0; i < noduri[u].size(); i++) {
		if (vizitat[noduri[u][i]] == ALB)
			dfs(noduri[u][i]);
	}	
	stiva.push(u);
}

void sortare_topologica () {
	int i;
	for (i = 1; i <= nr_noduri; i++)
		vizitat[i] = ALB;
	stiva.push(nr_noduri);	
	for (i = 1; i <= nr_noduri; i++)
		if (vizitat[i] == ALB)
			dfs(i);
}

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

	int i, x, y;
	scanf("%d %d", &nr_noduri, &nr_muchii);
	for (i = 1; i <= nr_muchii; i++) {
		scanf("%d %d", &x, &y);
		noduri[x].push_back(y);
	}

	sortare_topologica();

	while (!stiva.empty()) {
		printf("%d ", stiva.top());
		stiva.pop();
	}
	printf("\n");

	return 0;
}