golang力扣leetcode 200.岛屿数量

package main
func numIslands(grid [][]byte) int {
  cnt := 0
  for i := 0; i < len(grid); i++ {
    for j := 0; j < len(grid[i]); j++ {
      if grid[i][j] == '1' {
        dfs(grid, i, j)
        cnt++
      }
    }
  }
  return cnt
}
func dfs(grid [][]byte, i, j int) {
  if i < 0 || i >= len(grid) || j < 0 || j >= len(grid[0]) {
    return
  }
  if grid[i][j] == '1' {
    grid[i][j] = '0'
    dfs(grid, i-1, j)
    dfs(grid, i+1, j)
    dfs(grid, i, j-1)
    dfs(grid, i, j+1)
  }
  return
}
func main() {
}