Word Boggle

class Solution {
public:

bool solve(vector<vector<char>>&b,int x,int y, int pos, string str,int r,int c)
{
     int dx[]={1,1,0,-1,-1,-1,0,1};
        int dy[]={0,-1,-1,-1,0,1,1,1};
        if(pos==str.length())
        return true;
        for(int i=0;i<8;i++)
        {
            int nx =x+dx[i];
            int ny=y+dy[i];
            if(nx<r&&nx>=0&&ny<c&&ny>=0&&b[nx][ny]==str[pos])
            {
                char ch=b[nx][ny];
                b[nx][ny]='#';
                if(solve(b,nx,ny,pos+1,str,r,c)==true)
                {
                     b[nx][ny]=ch;
                return true;
                }
                 b[nx][ny]=ch;
               
            }
        }
        return false;
}
	vector<string> wordBoggle(vector<vector<char> >& b, vector<string>& d) {
	  int r=b.size();
	  int c=b[0].size();
	  vector<string>ans;
	  for(auto itr:d)
	  {
	      bool flag=false;
	      for(int i=0;i<r;i++)
	      {
	          for(int j=0;j<c;j++)
	          {
	              if(b[i][j]==itr[0])
	              {
	                  char ch=b[i][j];
                      b[i][j]='#';
	                  if(solve(b,i,j,1,itr,r,c)==true)
	                  {
	                        b[i][j]=ch;
	                      ans.push_back(itr);
	                      flag=true;
	                      break;
	                  }
	                  b[i][j]=ch;
	              }
	              
	          }
	          if(flag)
	          break;
	      }
	  }
	  return ans;
	}
};