Cod sursa(job #2755562)

Utilizator BalaBossBalaBoss BalaBoss Data 27 mai 2021 17:28:57
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <bits/stdc++.h>
#define M 400001
#define N 200001
using namespace std;
ifstream fin ("apm.in");
ofstream fout ("apm.out");

    int n,m,x,y,z,cost,nr;
    int t[N],h[N];

struct lista
{
    int x,y,c,sel;
};
    lista l[M];

bool cmp(lista A ,lista B)
{
    return A.c<B.c;
}

void Citire()
{
    fin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y>>z;
        l[i].x=x;l[i].y=y;l[i].c=z;l[i].sel=0;
    }
}

int root(int x)
{
    while(t[x]!=x)
        x=t[x];
    return x;
}

void Uniune(int x,int y)
{
    if(h[x]>h[y])
        t[y]=x;
    else if(h[y]>h[x])
        t[x]=y;
    else
    {
        h[x]++;
        t[y]=x;
    }
}

void Kruskal()
{
    for(int i=1;i<=n;++i)
    {
        t[i]=i;
        h[i]=1;
    }
    sort(l+1,l+m+1,cmp);
    cost=0;nr=0;
    for(int i=1;i<=m&&nr<n-1;i++)
    {
        int r1=root(l[i].x);
        int r2=root(l[i].y);
            if(r1!=r2)
        {
            Uniune(r1,r2);
            nr++;
            cost+=l[i].c;
            l[i].sel=1;
        }
    }

    fout<<cost<<'\n';
    fout<<n-1<<'\n';
    for(int i=1;i<=m;++i)
        if(l[i].sel==1)
        fout<<l[i].x<<" "<<l[i].y<<'\n';
}

int main()
{
    Citire();
    Kruskal();
    return 0;
}