從零開始學golang之Dijkstra

package main

import (
    "fmt"
)

const MAX_SIZE int = 5
const MAX_VALUE int = 9999

func main() {
    fmt.Println("Dijkstra")
    var gg Graph
    var vexs = []string{"A", "B", "C", "D", "E"}
    gg.vexnum = 5
    gg.vexs = vexs
    initGG(&gg, vexs)
    PrintG(gg, 5)
    Dijkstra(&gg, 1)
}

type Graph struct {
    vexs   []string                //定點集合
    vexnum int                     //定點數量
    edgnum int                     //邊數量
    matrix [MAX_SIZE][MAX_SIZE]int //鄰接矩陣
}

type Edge struct {
    start  string
    end    string
    weight int
}

func Dijkstra(gg *Graph, start int) {

    var dist [MAX_SIZE]int //路勁長度陣列
    var ss [MAX_SIZE]bool  //最短路勁節點集合

    //init
    dist = gg.matrix[start]
    ss[start] = true //find start to start
    dist[start] = 0  //start to start length

    for i := 0; i < gg.vexnum; i++ {
        k := 0
        min := MAX_VALUE
        fmt.Println("-----------")
        fmt.Println(dist, ss)
        //find next 貪心
        for j := 0; j < len(dist); j++ {
            if ss[j] == false && dist[j] != MAX_VALUE && dist[j] < min {
                min = dist[j]
                k = j
            }
        }

        //set find
        ss[k] = true

        //update dist length
        for u := 0; u < gg.vexnum; u++ {
            if gg.matrix[k][u] != MAX_VALUE && ss[u] == false {
                weight := min + gg.matrix[k][u]
                if weight < dist[u] {
                    dist[u] = weight
                }
            }
        }

    }

    for i := 0; i < gg.vexnum; i++ {
        fmt.Printf("shortest %s->%s = %d\n", gg.vexs[start], gg.vexs[i], dist[i])
    }
}

func initGG(gg *Graph, vexs []string) {
    for i := 0; i < len(vexs); i++ {
        for j := 0; j < len(vexs); j++ {
            gg.matrix[i][j] = MAX_VALUE
        }
    }
    gg.matrix[0][1] = 5
    gg.matrix[0][2] = 3

    gg.matrix[1][0] = 5
    gg.matrix[1][3] = 99
    gg.matrix[1][4] = 4

    gg.matrix[2][0] = 3
    gg.matrix[2][3] = 6

    gg.matrix[3][1] = 7
    gg.matrix[3][2] = 6
    gg.matrix[3][4] = 1

    gg.matrix[4][1] = 4
    gg.matrix[4][3] = 1

    gg.edgnum = 12 / 2
}

func PrintG(gg Graph, l int) {
    for i := 0; i < l; i++ {
        fmt.Println(gg.matrix[i])
    }
}

喜歡拉程式碼得兄弟自己下載

https://github.com/godla/golang-sort-data-structures-study.git

一起每天寫一點