Cod sursa(job #567709)

Utilizator alex25Muscalu Alexandra alex25 Data 30 martie 2011 13:26:03
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include<stdlib.h>
#include<fstream.h>
#define NM 200001
#define MM 400001
#define endl "\n"

ifstream in("apm.in");
ofstream out("apm.out");
struct muchie{ int x,y,c;
						 };
int n,m,L[NM];
muchie v[MM],h[NM];

void citire(){
int i;
in>>n>>m;
for(i=0;i<m;i++) in>>v[i].x>>v[i].y>>v[i].c;
}

int fcmp(void const *a,void const *b){
return ((muchie*)a)->c-((muchie*)b)->c;
}

int min(int x, int y){
if(x<y) return x;
return y;
}

int max(int x,int y){
if(x>y) return x;
return y;
}

int find(int x){
if(x==L[x]) return x;
else return find(L[x]);
}

void Union(int x, int y){
int px=find(x);
int py=find(y);
if(px<py) L[py]=px;
	else L[px]=py;
}

int main(){
int i,ms=0,j,ct=0;
citire();
qsort(v,m,sizeof(v[0]),fcmp);
for(i=1;i<=n;i++) L[i]=i;
i=0;
while(ms<n-1){

int px, py;
do{ px=find(v[i].x);
		py=find(v[i].y);
		if(px==py) i++;
	 }
 while(px==py);

 h[ms]=v[i];
 ms++;
 ct=ct+v[i].c;


 int a=max(px,py);
 int b=min(px,py);
 Union(b,a);
}


//for(j=1;j<=n;j++)
//f(L[j]==b) L[j]=a;
//for(j=1;j<=n;j++)
//if(L[j]==L[v[i].y]) L[j]=L[v[i].x];


out<<ct<<endl<<n-1<<endl;;
for(i=0;i<n-1;i++) out<<h[i].x<<" "<<h[i].y<<endl;

return 0;
		}