golang实现kruskal最小生成树

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
	"sync"
)

type Edge struct {
	u   int
	v int
	w  int
}
var cnt int
var fa [200005] int


type shuzu []Edge

func (a shuzu) Len() int {
	return len(a)
}
func (a shuzu) Less(i, j int) bool {
	return a[i].w < a[j].w
}
func (a shuzu) Swap(i, j int) {
	a[i], a[j] = a[j], a[i]
}

func main() {
	n := ReadInt()
	m := ReadInt()
	edge := make([]Edge, m+1)
	for i := 1; i <= m; i++ {
		edge[i].u = ReadInt()
		edge[i].v = ReadInt()
		edge[i].w = ReadInt()
	}
	for i := 1; i <= n+1; i++ {
		fa[i] = i;
	}
	sort.Sort(shuzu(edge))
	var tot int = 0
	var ans int64 = 0
	for i := 1; i <= m; i++ {
		u := find(edge[i].u)
		v := find(edge[i].v)
		if u != v {
			ans += int64(edge[i].w)
			fa[u] = v
			tot++
		}
		if tot == n-1 {
			break;
		}
	}
	if tot==n-1 {
		fmt.Println(ans)
	} else {
		fmt.Println(-1)
	}

}

////////////////////////////////////
func find(x int) int {
	p := x
	var tmp int = 0
	for p