30 -【leetcode】DFS 岛屿的最大面积

[wordlex]

https://leetcode-cn.com/problems/max-area-of-island/

[FE92star]

​/**
 * @param {number[][]} grid
 * @return {number}
 */
var maxAreaOfIsland = function(grid) {
    let row = grid.length, col = grid[0].length // 网格的宽高
    function dfs (x, y) { // 计算网格四周值为1的节点
        if (x < 0 || x >= row || y < 0 || y >= col || grid[x][y] === 0) return 0
        grid[x][y] = 0
        let ans = 1, dx = [-1, 1, 0, 0], dy = [0, 0, 1, -1]
        for (let i = 0; i < dx.length; i++) {
            ans += dfs(x + dx[i], y + dy[i])
        }
        return ans
    }
    let res = 0
    // 二元数组双重遍历
    for (let i = 0; i < row; i++) {
        for (let j = 0; j < col; j++) {
            res = Math.max(res, dfs(i, j))
        }
    }
    return res
}