Cod sursa(job #302611)

Utilizator skatesZaharescu Dragos skates Data 9 aprilie 2009 07:28:06
Problema Arbore partial de cost minim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.23 kb
#include <fstream.h>     
#define NMAX 200001
#define MMAX 400001
ifstream f("apm.in");
ofstream g("apm.out");
int n,m,L[NMAX];
struct muchie{int x,y,c;};
muchie u[MMAX],v[MMAX];

int divide(int s, int d)
{int aux, i=s, j=d, pi=0, pj=1;
 muchie aux1;
 while(i<j)
  {if(u[i].c>u[j].c) {aux1=u[i]; u[i]=u[j]; u[j]=aux1; aux=pi; pi=pj; pj=aux;}
   i+=pi; j-=pj;                     
  }    
 return i;
}   
  
void init()    
{for (int i=1;i<=n;i++) L[i]=i;   
}     
  
void citire()     
{int i,x,y,c; f>>n>>m;     
  for(i=1;i<=m;i++) {f>>x>>y>>c; u[i].x=x; u[i].y=y; u[i].c=c;}     
  f.close();     
}     
  
void sortare(int s, int d)     
{int m;   
 if(s<d) {m=divide(s,d); sortare(s, m-1); sortare(m+1, d);}   
}     
  
int main()     
{int i=1,j,k=0,x,y;
 long long ct=0;
 citire();     
 sortare(1, m);     
 init();     
 while(k<n-1)     
  {if (L[u[i].x]!=L[u[i].y])     
    {k++; ct=ct+u[i].c;     
     v[k]=u[i];     
     x=L[u[i].y];     
     y=L[u[i].x];   
     for (j=1;j<=n;j++) if(L[j]==x) L[j]=y;     
    }    
   i++;     
  }     
 g<<ct<<'\n'<<n-1<<'\n';     
 for(i=1; i<n; i++)     
  g<<v[i].x<<' '<<v[i].y<<'\n';     
 g.close(); f.close();     
 return 0;     
}