代码：

class Solution {int[][] dirs = {{-1,0},{1,0},{0,1},{0,-1}};public int maxAreaOfIsland(int[][] grid) {int max = 0;for(int i=0;i<grid.length;i++){for(int j=0;j<grid[0].length;j++){if(grid[i][j]==1){int[] start = {i,j};int area = getArea(start,0,grid);max = max>area?max:area;}}}return max;}public int getArea(int[] start, int area, int[][] grid){grid[start[0]][start[1]] = -1;area++;for(int i=0;i<dirs.length;i++){int x = start[0]+dirs[i][0];int y = start[1]+dirs[i][1];if(x>=0&&x<grid.length&&y>=0&&y<grid[0].length&&grid[x][y]==1){int[] cur = {x,y};area = getArea(cur,area,grid);}}return area;}
}