Cod sursa(job #184361)

Utilizator wefgefAndrei Grigorean wefgef Data 23 aprilie 2008 16:10:37
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

#define FILEIN "dijkstra.in"
#define FILEOUT "dijkstra.out"

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

int N, M;
vector< pair<int, int> > G[MAXN];
int Dmin[MAXN];

void ReadData() {
	ifstream fin(FILEIN);

	fin >> N >> M;
	for (int i = 0; i < M; ++i) {
		int a, b, c;

		fin >> a >> b >> c;
		G[a].push_back(make_pair(b, c));
	}
}

void Solve() {
	bool InQueue[MAXN];
	queue<int> Q;

	memset(Dmin, INF, sizeof(Dmin));
	memset(InQueue, false, sizeof(InQueue));

	for (Q.push(1), Dmin[1] = 0, InQueue[1] = true; !Q.empty(); InQueue[Q.front()] = false, Q.pop())
		for (vector< pair<int, int> >::iterator it = G[Q.front()].begin(); it != G[Q.front()].end(); ++it)
			if (Dmin[Q.front()] + it->second < Dmin[it->first]) {
				Dmin[it->first] = Dmin[Q.front()] + it->second;
				if (!InQueue[it->first]) {
					Q.push(it->first);
					InQueue[it->first] = true;
				}
			}
}

void WriteData() {
	ofstream fout(FILEOUT);

	for (int i = 2; i <= N; ++i)
		fout << (Dmin[i] < INF ? Dmin[i] : 0) << " ";
}

int main() {
	ReadData();
	Solve();
	WriteData();
}