广度优先搜索

由 0- 1 组成的迷宫
从这个迷宫出去
0是可以行走的路
1是墙,无法通过
6 5
0 1 0 0 0
0 0 0 1 0
0 1 0 1 0
1 1 1 0 0
0 1 0 0 1
0 1 0 0 0
打印出行走的路线
  0   0   4   5   6 
  1   2   3   0   7 
  2   0   4   0   8 
  0   0   0  10   9 
  0   0  12  11   0 
  0   0  13  12  13

package main

import (
    "fmt"
    "os"
)

func readMaze(filename string) [][]int {
    file, err := os.Open(filename)
    if err != nil {
        panic(err)
    }
    var row, col int
    fmt.Fscanf(file, "%d %d", &row, &col)
    maze := make([][]int, row)
    for i := range maze {
        maze[i] = make([]int, col)
        for j := range maze[i] {
            fmt.Fscanf(file, "%d", &maze[i][j])
        }
    }
    return maze
}

type point struct {
    i, j int
}

var dirs = [4]point{
    {-1, 0}, {0, -1}, {1, 0}, {0, 1},
}

func (p point) add (r point) point  {
    return point{p.i + r.i, p.j + r.j}
}

func (p point) at(g [][]int) (int, bool)  {
    if p.i < 0 || p.i >= len(g) {
        return 0, false
    }
    if p.j < 0 || p.j >= len(g[p.i]) {
        return 0, false
    }
    return g[p.i][p.j], true
}

func walk(maze [][]int, start point, end point) [][]int {
    steps := make([][]int, len(maze))
    for i := range steps {
        steps[i] = make([]int, len(maze[i]))
    }

    q := []point{start}
    for len(q) > 0 {
        cur := q[0]
        q = q[1:]

        if cur == end {
            break
        }
        for _, dir := range dirs {
            next := cur.add(dir)
            val, ok := next.at(maze)
            if val == 1 || !ok {
                continue
            }
            val, ok = next.at(steps)
            if !ok || val != 0 {
                continue
            }
            if next == start {
                continue
            }
            curSteps, _ := cur.at(steps)
            steps[next.i][next.j] = curSteps + 1

            q = append(q, next)
        }
    }
    return steps
}

func main() {
    maze := readMaze("./maze.in")
    for _, row := range maze {
        for _, val := range row {
            fmt.Printf("%d ", val)
        }
        fmt.Println()
    }
    fmt.Println()
    steps := walk(maze, point{0, 0}, point{len(maze) -1, len(maze[0]) - 1})
    for _, row := range steps {
        for _, col := range row {
            fmt.Printf("%3d ", col)
        }
        fmt.Println()
    }
}