Union lookup template with path compression:

Union lookup template with path compression:

class UnionFind{
public:
    vector<int>father;
    UnionFind(int num){//num表示元素的个数
        for(int i = 0; i < num; i++){
            father.push_back(i);//箭头指向自己
        }
    }
    int Find(int n){
        //递归
        if(father[n] == n)
            return n;
        father[n] = Find(father[n]);//路径压缩版本
        return father[n];
    }
    void Union(int a, int b){
        int fa = Find(a);
        int fb = Find(b);
        father[fb] = fa;
    }
};

Kruscal simple template:

#include <cstdio>
#include <algorithm>
#include <cstring>
#include <iostream>
using namespace std;
int n,p;
int node[10001]; 
int f[10001]; 
struct E{
	int x,y,d; //x、y 结点间距离
}e[100001];
bool cmp(E e1, E e2){
	return e1.d < e2.d;
}
int find(int x){
	return f[x] == x ? x : f[x] = find(f[x]);
}
void merge(int x,int y){
	int tx = find(x);
	int ty = find(y);
	if(tx != ty){
		f[ty] = tx;
	}
}
bool same(int x,int y){
	return find(x) == find(y);
}
int Kruscal(){
	int ans = 0;
	sort(e,e+p,cmp);
	for(int i = 0; i < p; i++){
		if(!same(e[i].x,e[i].y)){
			merge(e[i].x,e[i].y);
			ans += e[i].d;
		}
	}
	return ans;
}
void init(){
	scanf("%d%d",&n,&p);
	for(int i = 1; i <= p; i++){
		scanf("%d%d%d",&e[i].x, &e[i].y, &e[i].d);
	}
	for(int i = 1; i <= n; i++){
		f[i] = i;
	}
}
int main(){
	init();
	int result = Kruscal();
	for(int i = 1;i <= n;i++){
        if(!same(i,1)){
            result = -1;
        }
    }
	if(result != -1){
		cout << result << endl;	
	}else{
		cout << "orz" << endl; 
	}
	return 0;
}