[Golang] DFS
Convert the n x n grid to a 3n x 3n board, and dfs just like Question 200.\n\n\nfunc regionsBySlashes(grid []string) int {\n    n := len(grid)\n    board := mak
Convert the `n x n` grid to a `3n x 3n` board, and dfs just like [Question 200](https://leetcode.com/problems/number-of-islands/).\n\n```\nfunc regionsBySlashes(grid []string) int {\n    n := len(grid)\n    board := make([][]int, n*3)\n    for i := 0; i < n*3; i++ {\n        board[i] = make([]int, n*3)\n    }\n    \n    for i := 0; i < n; i++ {\n        for j := 0; j < n; j++ {\n            if grid[i][j] == \'/\' {\n                board[i*3][j*3+2] = 1\n                board[i*3+1][j*3+1] = 1\n                board[i*3+2][j*3] = 1\n            } else if grid[i][j] == \'\\\\\' {\n                board[i*3][j*3] = 1\n                board[i*3+1][j*3+1] = 1\n                board[i*3+2][j*3+2] = 1\n            }\n        }\n    }\n        \n    count := 0\n    for i := 0; i < len(board); i++ {\n        for j := 0; j < len(board); j++ {\n            if board[i][j] == 0 {\n                dfs(board, i, j)\n                count++\n            }\n        }\n    }\n    \n    return count\n}\n\nfunc dfs(board [][]int, i, j int) {\n    if i < 0 || i >= len(board) || j < 0 || j >= len(board) || board[i][j] != 0 {\n        return\n    }\n    \n    board[i][j] = 1\n    \n    dfs(board, i-1, j)\n    dfs(board, i+1, j)\n    dfs(board, i, j-1)\n    dfs(board, i, j+1)\n}\n```
['Depth-First Search', 'Go']