Golang force buckle leetcode 1020 Number of enclaves

1020. The number of enclaves

1020. The number of enclaves

Answer key

BFS perhaps DFS, The idea of this question is to take the border as the search point , Then what can be searched is what can be accessed , In the code vis, You can calculate what you can't find by traversing , That's the answer

Code

package main

func numEnclaves(grid [][]int) int {
    
	var dirs = []struct{
     x, y int }{
    {
    -1, 0}, {
    1, 0}, {
    0, -1}, {
    0, 1}}
	var vis = make([][]bool, len(grid))
	for i, v := range grid {
    
		vis[i] = make([]bool, len(v))
	}
	var dfs func(int, int)
	dfs = func(x, y int) {
    
		if x < 0 || x >= len(grid) || y < 0 || y >= len(grid[0]) || vis[x][y] || grid[x][y] == 0 {
    
			return
		}
		vis[x][y] = true
		for _, v := range dirs {
    
			dfs(x+v.x, y+v.y)
		}
	}
	for i := range grid {
    
		dfs(i, 0)
		dfs(i, len(grid[0])-1)
	}
	for i := 0; i <= len(grid[0])-1; i++ {
    
		dfs(0, i)
		dfs(len(grid)-1, i)
	}
	ans := 0
	for i, v := range grid {
    
		for j := range v {
    
			if grid[i][j] == 1 && vis[i][j] == false {
    
				ans++
			}
		}
	}
	return ans
}