Cod sursa(job #563420)

Utilizator catalin93Catalin Ionescu catalin93 Data 25 martie 2011 08:18:27
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include<stdio.h>
#include<queue>
#include<vector>
using namespace std;

const int N=250000;
const int INF=307500000;

struct succesor 
{
	int vf,cost;
};

vector<succesor> a[N];
priority_queue< pair<int,int> >h;
int n,x0,d[N],pred[N];
bool s[N];

void eu_ma_chinui_sa_citesc()
{
	int m,i,x,y,c;
	scanf("%d%d",&n,&m);
	x0 = 1;
	for(i=1;i<=n;i++)
	{
		scanf("%d%d%d",&x,&y,&c);
		a[x].push_back((succesor){y,c});
	}
}

int vf_cost_minim()
{

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

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

int main()
{
	freopen("dijkstra.in","r",stdin);
	freopen("dijkstra.out","w",stdout);
	
	eu_ma_chinui_sa_citesc();
	eu_il_implementez_pe_djikistra_asta();
	eu_afisez_cu_multe_dificultati();
	
	return 0;
}