Cod sursa(job #565859)

Utilizator chrisuPirvu Cristina chrisu Data 28 martie 2011 12:56:42
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include<stdio.h>
#include<queue>
#include<vector>
using namespace std;

const int N=50715;
const int INF=1000000000;

struct succesor 
{
	int vf,cost;
};

vector<succesor> a[N];
priority_queue<pair<int,int> > h;
int n,d[N];
bool s[N];

void read()
{
	int m,i,x,y,c;
	scanf("%d%d",&n,&m);
	for(i=1;i<=m;i++)
	{
		scanf("%d%d%d",&x,&y,&c);
		a[x].push_back((succesor){y,c});
	}
}

int vf_cost_minim()
{

	while(!h.empty())
	{
		if(!s[h.top().second])
			return h.top().second;
		h.pop();
	}
	return 0;
}

void eu_actualizez(int x)
{
	int y,c;
	for(size_t i=0;i<a[x].size();i++)
	{
		y=a[x][i].vf;
		c=a[x][i].cost;
		if(d[x] + c < d[y])
		{
			d[y] = d[x] + c;
			h.push(make_pair(-d[y],y));
		}
	}
}
void init()
{
	int i;
	for(i=0;i<=n;i++)
		d[i] = INF;
}
void dijkstra(int x0)
{
	int x;
	d[x0]=0;
	h.push(make_pair(d[x0],x0));
	for(int i=1;i<n;i++)
	{
		x = vf_cost_minim();
		if(d[x] == INF)
			return ;
		s[x] = true;
		eu_actualizez(x);
	}
}
	
void print()
{
	int i;
	for(i=2;i<=n;i++)
		if(d[i] == INF)
			printf("0 ");
		else
			printf("%d ", d[i]);
}

int main()
{
	freopen("dijkstra.in","r",stdin);
	freopen("dijkstra.out","w",stdout);
	
	read();
	init();
	dijkstra(1);
	print();
	
	return 0;
}