class Solution {

public:

    vector<vector<int>> dirs={{,},{,},{,},{,-},{,-},{-,-},{-,},{-,}};

    void gameOfLife(vector<vector<int>>& board) {

        //time O(2*9*m*n)

        int r=board.size();

        if(r==) return;

        int c=board[].size();

        if(c==) return;

        vector<vector<int>> cur(r,vector(c,));

        for(int i=;i<r;i++){

            for(int j=;j<c;j++){

                for(auto dir:dirs){

                    int x=i+dir[],y=j+dir[];

                    if(x< || x>=r || y< || y>=c) continue;

                    cur[i][j]+=board[x][y];

                }

            }

        }

        for(int i=;i<r;i++){

            for(int j=;j<c;j++){

                if( cur[i][j]== || board[i][j]== && cur[i][j]== )

                    board[i][j]=;

                else

                    board[i][j]=;

            }

        }

    }

};