go语言广度优先算法走迷宫

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

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 {
         return steps
      }
      for _, dir := range dirs {
         next := cur.add(dir)

         //maze at next is 0
         //and steps at next is 0
         //and next != start
         val, ok := next.at(maze)
         if !ok || val == 1 {
            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/maze")
   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 _, val := range row {
         fmt.Printf("%2d ", val)
      }
      fmt.Println()
   }
}

 

输出结果:

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 

 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