Cod sursa(job #1356374)

Utilizator killlerr1Chilom Mircea killlerr1 Data 23 februarie 2015 13:30:39
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream is("dijkstra.in");
ofstream os("dijkstra.out");


const int MAXN = 50001, INF = 1 << 30;


struct Edge{
	int node, cost;
	const bool operator <( const Edge& e) const
	{
		return cost > e.cost;
	}
};

priority_queue <Edge> Q;

typedef vector<int> VI;
vector<vector<Edge> > G;
bool vis[MAXN];
int dmin[MAXN];
int n;
int m;

void Read();
void Dijkstra(int nod);
void Write();


int main()
{
	Read();
	Dijkstra(1);
	Write();

	is.close();
	os.close();
	return 0;
}

void Read()
{
	int a, b, c;
	is >> n;
	G.resize(n+1);
	is >> m;
	for( int i = 1; i <= m; ++i )
	{
		is >> a >> b >> c;
		G[a].push_back({b, c});
	}
}

void Write()
{
	for( int i = 2; i <= n; ++i )
		os << dmin[i] << ' ';
}

void Dijkstra(int nod)
{
	for( int i = 1; i <= n; ++i )
		dmin[i] = INF;
	dmin[1] = 0;
	Q.push({nod, 0});

	while(!Q.empty())
	{
		nod = Q.top().node;
		vis[nod] = true;

		for( auto e : G[nod] )
		{
			if( !vis[e.node] && dmin[nod] + e.cost < dmin[e.node] )
			{
				dmin[e.node] = e.cost + dmin[nod];
				Q.push({e.node, dmin[e.node]});
			}
		}

		while( !Q.empty() && vis[Q.top().node] )
			Q.pop();

	}


}