Cod sursa(job #2696883)

Utilizator StefanaArinaStefana Arina Tabusca StefanaArina Data 17 ianuarie 2021 01:48:14
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb
	
#include<iostream>
#include<fstream>
#include<string.h>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
 
using namespace std;
 
#define x first
#define y second
#define NMAX 100005
 
ifstream f("apm.in");
ofstream g("apm.out");
 
int father[NMAX], group[NMAX], n, m, answer;
vector< pair<int, pair<int, int> > > edges;
vector< pair<int, int> > apm;
 
int findFather(int node) {
    if(node == father[node])
        return node;
    int new_father = findFather(father[node]);
    father[node] = new_father;
    return new_father;
}
 
int main () {
    int a, b, cost;
    
    f>>n>>m;
    for(int i = 1; i <= m; i++) {
        f>>a>>b>>cost;
        edges.push_back(make_pair(cost, make_pair(a, b)));
    }
    sort(edges.begin(), edges.end());
    
    for(int i = 1; i <= n; i++) {
        father[i] = i;
        group[i] = 1;
    }
    
    for(auto edge : edges) {
        int a = edge.second.first;
        int b = edge.second.second;
        
        int fa = findFather(a);
        int fb = findFather(b);
        
        if(fa == fb) {
            continue;
        }
        
        apm.push_back(edge.second);
        answer += edge.first;
        
        if(group[fa] > group[fb]) {
            father[fb] = fa;
            group[fa] += group[fb];
        }
        else {
            father[fa] = fb;
            group[fb] += group[fa];
        }
    }
    
    g<<answer<<endl<<n - 1<<endl;
    for(auto edge : apm) {
        g<<edge.first<<" "<<edge.second;
        g<<endl;
    }
    
    return 0;
}