Cod sursa(job #989976)

Utilizator Cosmin1490Balan Radu Cosmin Cosmin1490 Data 27 august 2013 03:21:18
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.75 kb
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
using namespace std;
  
const string file = "dijkstra";
  
const string infile = file + ".in";
const string outfile = file + ".out";

vector<vector<pair<int, int> > > G;
vector<int> dist;
const int INF = 0x3f3f3f3f;

set<pair<int, int> > q;

void Dijkstra()
{
	dist[1] = 0;

	q.insert(make_pair(0, 1));

	while(q.empty() == false)
	{
		int current = q.begin()->second;
		q.erase(q.begin());

		for(vector<pair<int, int> >::iterator itr = G[current].begin();
			itr != G[current].end();
			itr++)
		{
			if(dist[itr->first] > dist[current] + itr->second)
			{

				if(dist[itr->first] != INF)
				{
					q.erase(q.find(make_pair(dist[itr->first], itr->first)));
				}


				dist[itr->first] = dist[current] + itr->second;
				q.insert(make_pair(dist[itr->first], itr->first));
			}
		}

	}


}


int main()
{
	fstream fin(infile.c_str(), ios::in);
	int N, M;
	fin >> N >> M;

	G.resize(N + 1);
	dist.resize(N + 1, INF);

	for(int i = 0; i < M; i++)
	{
		int x, y, c;
		fin >> x >> y >> c;
		G[x].push_back(make_pair(y, c));
	}
	fin.close();

	Dijkstra();

	fstream fout(outfile.c_str(), ios::out);

	for(int i = 2; i <= N; i++)
	{
		fout << ((dist[i] == INF) ? 0 : dist[i]) << " ";
	}
	fout << "\n";
	fout.close();
}