Cod sursa(job #712347)

Utilizator swim406Teudan Adina swim406 Data 13 martie 2012 12:43:18
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include<fstream>
#include<limits>
using namespace std;
#define inf 250000000
long long n,d[50001],m;
struct graf {
	int x,y,z;
}; 
graf arc[250001];
int dist(int a, int b) {
	int k=-1;
	for(int i=1;i<=m;i++)
		if(arc[i].x==a && arc[i].y==b) {
			k=arc[i].z;
			i=m+1;
		}
	return k;
}
void dijkstra(int x0) {
	int i,min,k,ok=1,viz[50001],tata[50001],p;
	for(i=1;i<=n;i++) {
		p=dist(x0,i);
		if(p==-1) d[i]=inf;
		else d[i]=p;
		tata[i]=x0;
		viz[i]=0;
	}
	tata[x0]=0;
	viz[x0]=1;
	while(ok) {
		min=inf;
		for(i=1;i<=n;i++) 
			if(!viz[i] && min>d[i]) {
				min=d[i];
				k=i;
			}
		if(min!=inf) {
			viz[k]=i;
			for(i=1;i<=n;i++) {
				p=dist(k,i);
				if(p==-1) p=inf;
				if(!viz[i] && d[i]>d[k]+p) {
					d[i]=d[k]+p;
					tata[i]=k;
				}
			}
		}
		else ok=0;
	}
}
int main() {
	ifstream f("dijkstra.in");
	ofstream g("dijkstra.out");
	int i,x0;
	f>>n>>m;
	x0=1;
	for(i=1;i<=m;i++)
		f>>arc[i].x>>arc[i].y>>arc[i].z;
	dijkstra(x0);
	for(i=2;i<=n;i++) 
		if(d[i]!=inf) g<<d[i]<<" ";
		else g<<0<<" ";
	return 0;
}