695. Max Area of Island

class Solution {public:    int DFS(vector<vector<int>>& grid, int x, int y, int size) {        if (x < 0 || y < 0 || x >= grid.size() || y >= grid[0].size() ||            grid[x][y] == 0)            return size;        grid[x][y] = 0;        return 1 + DFS(grid, x + 1, y, size) + DFS(grid, x - 1, y, size) +               DFS(grid, x, y + 1, size) + DFS(grid, x, y - 1, size);    }    int maxAreaOfIsland(vector<vector<int>>& grid) {        // loop through each cell, x,y and run DFS on each but for each        // successful run, add one to the island size. and double for loop        // here will do the maxing strat        int best = 0;        for (int i = 0; i < grid.size(); i++) {            for (int j = 0; j < grid[0].size(); j++) {                int result = DFS(grid, i, j, 0);                best = max(result, best);            }        }        return best;    }};