Description

左上角为起点，右下角为终点，1为墙，0为路，起点到终点的步数

Input

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

Output

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

Code

package main

import (
    "os"
    "fmt"
)

func readMaze(filename string) [][]int { //从文件中读取
    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 { //点
    i, j int
}

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

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

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

func walk(maze [][]int, start, 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 !ok || val != 0 {
                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")

    steps := walk(maze, point{0,0},point{len(maze),len(maze[0])})

    for _, row := range steps {
        for _, val := range row {
            fmt.Printf("%3d",val)
        }
        fmt.Println()
    }

}