Cod sursa(job #549104)

Utilizator popadanielpopadaniel popadaniel Data 8 martie 2011 10:05:24
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include<fstream.h>
#include<limits.h>
#define NM 100
#define INF (INT_MAX-10)/2
int c[NM][NM],d[NM],s[NM],prec[NM],n,m,start=1;
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
void build(){
int i,j,x,y,cost;
in>>n>>m;
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
c[i][j]=INF;
for(i=1;i<=n;i++)
c[i][i]=0;
for(i=1;i<=m;i++){
in>>x>>y>>cost;
c[x][y]=cost;
}
//in>>start j;
}
void init(){
int i;
s[start]=1;
for(i=1;i<=n;i++)
d[i]=c[start][i];
}
int minim(){
int m=INF*2,i,k;
for(i=1;i<=n;i++)
if(!s[i]&&d[i]<m){ m=d[i]; k=i; }
return k;
}

void dijkstra(){
int k,i,dc,nrs=1,gata=0;
do{
k=minim();
if(d[k]==INF||nrs==n) gata=1;
else{
s[k]=1;
nrs++;
for(i=1;i<=n;i++)
if(!s[i]){
dc=d[k]+c[k][i];
if(dc<d[i]){
d[i]=dc;
prec[i]=k;
}
}}
}while(!gata);
}
void drum(int x){
if(x){
drum(prec[x]);
cout<<x<<" ";
}
}
int main(){
int i;
build();
init();
dijkstra();
for(i=2;i<=n;i++)
if(d[i]<INF) out<<d[i]<<" ";
else out<<0<<" ";
return 0;
}