Cod sursa(job #1829852)

Utilizator jurjstyleJurj Andrei jurjstyle Data 15 decembrie 2016 19:02:16
Problema Algoritmul lui Dijkstra Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <fstream>
#include <vector>
#include <set>
using namespace std;


ofstream fout("dijkstra.out");
const int Inf = 0x3f3f3f3f;

using PII = pair<int, int>;
using VI = vector<int>;

vector<vector<PII>> G;
int n;
VI d;

void Read();
void Dijkstra(int x, VI& d);

int main()
{
	Read();
	Dijkstra(1, d);
	
	for (int x = 2; x <= n; ++x)
		if (d[x] != Inf)
			fout << d[x] << ' ';
		else
			fout << 0 << ' ';
			
	fout.close();
}

void Dijkstra(int x, VI& d)
{
	d = VI(n + 1, Inf);
	set<PII> Q;
	d[x] = 0;
	int dx, w, y; 
	for (Q.insert({0, x}); !Q.empty(); Q.erase(Q.begin()))
	{
		x = Q.begin()->second, dx = Q.begin()->first;
		
		if ( dx > d[x] )
			continue;
		
		for (auto& p : G[x])
		{
			y = p.second; w = p.first;
			if ( d[y] > d[x] + w )
			{
				d[y] = d[x] + w;
				Q.insert({d[y], y});
			}
		}
	}
}


void Read()
{
	ifstream fin("dijkstra.in");
	int m, x, y, w;
	fin >> n >> m;
	//G.resize(n + 1);
	G = vector<vector<PII>>(n + 1);
	while (m--)
	{
		fin >> x >> y >> w;
		G[x].push_back({w, y});
	}
	

	fin.close();
}