PIRM

package main

import (
    "fmt"
    "github.com/skorobogatov/input"
)
type Graph struct {
    value [][]int
    used []bool
    min_e []int
    sel_e []int
}
const INF = 2147483647
var v, result int
func PRIM(graph Graph) {
    graph.min_e[0] = 0
    for i := 0; i < len(graph.value); i++ {
        v = -1
        for j := 0; j < len(graph.value); j++ {
            if !graph.used[j] && (v == -1 || graph.min_e[j] < graph.min_e[v]) {
                v = j
            }
        }
        if graph.min_e[v] == INF {
            fmt.Println("No MST!")
            break
        }
        graph.used[v] = true
        if graph.sel_e[v] != -1 {
            result += graph.min_e[v]
        }
        for to := 0; to < len(graph.value); to++ {
            if graph.value[v][to] < graph.min_e[to] {
                graph.min_e[to] = graph.value[v][to]
                graph.sel_e[to] = v
            }
        }
    }
}
func main() {
    var n, m int
    var graph Graph
    input.Scanf("%d \n %d", &n, &m)
    graph.value = make([][]int, n)
    graph.used = make([]bool, n)
    graph.min_e = make([]int, n)
    graph.sel_e = make([]int,n)
    for i := 0; i < n; i++ {
        graph.value[i] = make([]int, n)
        for j := 0; j < n; j++ {
            graph.value[i][j] = INF
        }
    }
    for i := 0; i < n; i++ {
        graph.min_e[i] = INF
    }

    for i := 0; i < n; i++ {
        graph.sel_e[i] = -1
    }
    for i := 0; i < m; i++ {
        var indexA, indexB, dist int
        input.Scanf("%d %d %d", &indexA, &indexB, &dist)
        //graph[indexA] = append(graph[indexA], dist)
        graph.value[indexA][indexB] = dist
        graph.value[indexB][indexA] = dist
        //graph[indexB] = append(graph[indexB], dist)
    }
    //for i:=0;i < n; i++ {fmt.Println(min_e[i])}
    //for i:=0;i < n; i++ {fmt.Println(graph.value[i])}
    PRIM(graph)
    fmt.Println(result)
}