記錄一個demo，方便以后查閱

package main

import (
    "fmt"
    "os"
)

type point struct {
    i, j int
}

func main() {
    //讀取文件
    file, err := os.Open("./maze.in")
    defer file.Close()
    if err != nil {
        fmt.Errorf("read file fail: %v", err)
    }
    //獲取迷宮地圖的規格
    var row, col int
    fmt.Fscanf(file, "%d %d", &row, &col)
    //讀取迷宮地圖
    var maze = make([][]int, row)
    for i := range maze {
        maze[i] = make([]int, col)
        for j, val := range maze[i] {
            fmt.Fscanf(file, "%d", &val)
            maze[i][j] = val
        }
    }
    //生成一個迷宮路線圖steps
    var steps = make([][]int, len(maze))
    for i := range steps {
        steps[i] = make([]int, len(maze[i]))
    }
    //定義起始位置和結束位置
    start := point{0, 0}
    end := point{len(maze) - 1, len(maze[0]) - 1}
    //定義方向向量 逆時針（上左下右）
    direction := []point{
        {-1, 0},
        {0, -1},
        {1, 0},
        {0, 1},
    }
    //探索起始點，發現下一步
    var Q []point
    Q = append(Q, start)
    for {
        origin := Q[0]
        Q = Q[1:]
        //判斷是否探索到終點
        if origin == end {
            break
        }
        //逆時針方向探索隊列中取出的點
        for _, d := range direction {
            next := point{origin.i + d.i, origin.j + d.j}
            //判斷是否越界
            if next.i < 0 || next.i >= len(maze) {
                continue
            }
            if next.j < 0 || next.j >= len(maze[0]) {
                continue
            }
            //判斷是否為起始位置或者為墻壁
            if next == start || maze[next.i][next.j] == 1 {
                continue
            }
            //判斷是否已經探索過
            if steps[next.i][next.j] != 0 {
                continue
            }
            //畫出路線圖
            steps[next.i][next.j] = steps[origin.i][origin.j] + 1
            //把新發現的點加入隊列中等待探索
            Q = append(Q, next)
        }
    }
    //打印線路結果
    for _, step := range steps {
        for _, v := range step {
            fmt.Printf("%3d", v)
        }
        fmt.Println()
    }
}