package main

import (
  "os"
  "fmt"
  "strings"
  "strconv"
)

func main()  {
  arr := read("1.txt")
  ss := walk(arr, point{0, 0}, point{len(arr) - 1, len(arr[0]) - 1})
  for _,v := range ss{
    for _,vv := range v{
      fmt.Print(vv,"    ")
    }
    fmt.Println()
  }
}

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 walk(maze [][]int,start,end point) [][]int {

  //维护一个离原点多远可以到达的二维数组
  steps := make([][]int,len(maze))

  for k,_ := range steps{
    steps[k] = make([]int,len(maze[k]))
  }

  //将头放进队列
  Q := []point{start}
  for len(Q) > 0 {
    cur := Q[0]
    Q = Q[1:]

    if cur == end {
      break
    }

    //发现四个节点
    for _,dir := range dirs {
      next := cur.add(dir)
      val, ok := next.at(maze)
      //val等于说明撞墙了
      if !ok || val == 1 {
        continue
      }
      //走另一张图
      val, ok = next.at(steps)
      if !ok || val != 0 {
        continue
      }
      //是否回到了原点，因为maze和steps图中原点的值都是零
      if next == start {
        continue
      }

      //可以走了
      i, _ := cur.at(steps)
      steps[next.i][next.j] = i + 1
      //将该点加入队列继续找
      Q = append(Q,next)

    }

  }
  return steps

}

//是否撞墙了
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
  }
  //获取实现迷宫的值，如果是1的时候就撞墙了
  return grid[p.i][p.j],true
}

func read(filename string) [][]int {
  f, e := os.Open(filename)
  if e != nil {
    fmt.Println(e)
    panic(e)
  }
  defer f.Close()
  buf := make([]byte,1024)
  n, err := f.Read(buf)
  if err != nil {
    panic(err)
  }
  str := string(buf[:n])
  split := strings.Split(str, "\n")

  //获取行和列
  var row,col int
  ss := strings.TrimSpace(split[0])
  row, err = strconv.Atoi(strings.Split(ss, " ")[0])
  if err != nil {
    panic(err)
  }
  col, err = strconv.Atoi(strings.Split(ss, " ")[1])
  fmt.Println(col)
  if err != nil {
    panic(err)
  }

  arr := make([][]int,row)
  for k,_ := range arr{
    sArr := strings.Split(strings.TrimSpace(split[k + 1])," ")
    arr[k] = make([]int,5)
    for kk,_ := range arr[k]  {
      i, err := strconv.Atoi(sArr[kk])
      if err != nil {
        panic(err)
      }
      arr[k][kk] = i
    }
  }
  return arr
}