
class Solution {
public:
int dfs(vector<vector<int>>& grid, int x, int y){
int sum=1;
int row=grid.size();
int col=grid[0].size();
grid[x][y]=0;
vector<vector<int>> direction{{1,0},{-1,0},{0,1},{0,-1}};
for(int i=0;i<4;++i){
int x1=x+direction[i][0];
int y1=y+direction[i][1];
if(x1>=0 && x1<row && y1>=0 && y1<col && grid[x1][y1]==1)
sum+=dfs(grid,x1,y1);
}
return sum;
}
int maxAreaOfIsland(vector<vector<int>>& grid) {
int sum=0;
int row=grid.size();
int col=grid[0].size();
for(int i=0;i<row;++i)
for(int j=0;j<col;++j)
if(grid[i][j]==1)
sum=max(sum,dfs(grid,i,j));
return sum;
}
};