Cod sursa(job #1263058)

Utilizator pulseOvidiu Giorgi pulse Data 13 noiembrie 2014 21:11:56
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
#include <set>
#include <vector>
using namespace std;

const int MAXN = 50005;
const int INF = 0x3f3f3f3f;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

int N, M;
int D[MAXN];
vector < pair <int, int> > G[MAXN];
set < pair <int, int> > S;

void Dijkstra()
{
	for (int i = 2; i <= N; ++i)
		D[i] = INF;
	S.insert(make_pair(0, 1));
	while (!S.empty())
	{
		int node = S.begin() -> second;
		S.erase(S.begin());
		for (vector < pair <int, int> > :: iterator it = G[node].begin(); it != G[node].end(); ++it)
		{
			int v = it -> first;
			int cost = it -> second;
			if (D[v] > D[node] + cost)
			{
				if (D[v] != INF)
					S.erase(make_pair(D[v], v));
				D[v] = D[node] + cost;
				S.insert(make_pair(D[v], v));
			}
		}
	}
	for (int i = 2; i <= N; ++i)
		fout << ((D[i] != INF) ? D[i] : 0) << " ";
}

int main()
{
	fin >> N >> M;
	for (int i = 1, a, b, c; i <= M; ++i)
	{
		fin >> a >> b >> c;
		G[a].push_back(make_pair(b, c));
	}
	Dijkstra();
	fin.close(); fout.close();
	return 0;
}