Cod sursa(job #1930205)

Utilizator SagunistuStrimbu Alexandru Sagunistu Data 18 martie 2017 16:35:33
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.65 kb
#include <fstream>
#include <algorithm>
#define nmax 200005

using namespace std;

ifstream fin("apm.in");
ofstream fout("apm.out");

class DisjointSet
{
private:

    void Link(int x,int y)
    {
        if(a[x].r < a[y].r)
            a[x].p = y;
        else
        {
            a[y].p = x;
            if(a[y].r == a[x].r)
                a[x].r ++;
        }
    }

public:

    struct Elem
    {
        int p,r;
    };

    Elem a[nmax];

    void MakeSet(int x)
    {
        a[x].p = x;
        a[x].r = 0;
    }

    int FindSet(int x)
    {
        if(a[x].p != x)
            a[x].p = FindSet(a[x].p);
        return a[x].p;
    }

    void Union(int x,int y)
    {
        Link(FindSet(x),FindSet(y));
    }
};

struct muchie
{
    int x,y,c;
};

muchie a[nmax],tree[nmax];
int n,m,nr,s;
DisjointSet disjset;

void read()
{
    fin >> n >> m;
    for(int i = 1;i <= m;i++)
        fin >> a[i].x >> a[i].y >> a[i].c;
}

void kruskal()
{
    for(int i = 1;i <= n;i++)
        disjset.MakeSet(i);
    for(int i = 1;i <= m;i++)
    {
        if(disjset.FindSet(a[i].x) != disjset.FindSet(a[i].y))
        {
            disjset.Union(a[i].x,a[i].y);
            tree[++nr] = a[i];
            s += a[i].c;
        }
    }
}

void afisare()
{
    fout << s << "\n";
    fout << n - 1 << "\n";
    for(int i = 1;i <= nr;i++)
        fout << tree[i].x << " " << tree[i].y << "\n";
}

bool cmp(muchie x,muchie y)
{
    if(x.c < y.c)
        return true;
    return false;
}

int main()
{
    read();
    sort(a + 1,a + m + 1,cmp);
    kruskal();
    afisare();
    return 0;
}