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| func numIslands(grid [][]byte) int {
if len(grid) == 0 || len(grid[0]) == 0 {
return 0
}
m, n := len(grid), len(grid[0])
count := 0
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
if grid[i][j] == '1' {
count++
dfs(grid, i, j)
}
}
}
return count
}
func dfs(grid [][]byte, i, j int) {
if i < 0 || i >= len(grid) || j < 0 || j >= len(grid[0]) || grid[i][j] != '1' {
return
}
grid[i][j] = 2
dfs(grid, i-1, j)
dfs(grid, i+1, j)
dfs(grid, i, j-1)
dfs(grid, i, j+1)
}
|