Word Search

class Solution {
public:
    bool isExist(vector<vector<char>>& board,string wordsub,int h,int w, vector<vector<bool>>&flag)
    {
        int direct[4][2]={{0,1},{0,-1},{1,0},{-1,0}};
        for(int d=0;d<4;d++)
        {
            int jj=h+direct[d][0];
            int ii=w+direct[d][1];
            if(jj>=0&&jj<board.size()&&ii>=0&&ii<board[0].size())
            {
                if(wordsub[0]==board[jj][ii]&&flag[jj][ii]==0)
                {
                    flag[jj][ii]=1;
                    if(wordsub.size()==1||isExist(board,wordsub.substr(1),jj,ii,flag))
                        return true;
                    flag[jj][ii]=0;
                }
                
            }
                
        }
        return false;
    }
   
    bool exist(vector<vector<char>>& board, string word) {
        int length=word.size();
        int Height=board.size();
        int Width=board[0].size();
        vector<vector<bool>> flag(Height,vector<bool>(Width,0));
        for(int h=0;h<Height;h++)
            for(int w=0;w<Width;w++)
            {
                if(board[h][w]==word[0])
                {
                    flag[h][w]=1;
                    if( word.size()==1||isExist(board,word.substr(1),h,w,flag))
                        return true;
                    flag[h][w]=0;
                }
            }
        return false;
    }
};