Find the number of islands

//using grid array as visited array also and make it's 1 to 0,if visited that node.
void solve(vector<vector<char>>& grid,int x,int y,int n,int m){
       int dx[8]={0,0,1,-1,-1,-1,1,1};
       int dy[8]={1,-1,0,0,-1,1,1,-1};
       if(x<0 || y<0 || x>=n || y>=m || grid[x][y]=='0'){
           return;
       }
       grid[x][y]='0';
       for(int i=0;i<8;i++){
           int nx=x+dx[i];
           int ny=y+dy[i];
           solve(grid,nx,ny,n,m);
       }
   }

class Solution {
  public:
    // Function to find the number of islands.
    int numIslands(vector<vector<char>>& grid) {
        int n=grid.size();
       int m=grid[0].size();
       int ans=0;
       queue<pair<int,int>> q;
       for(int i=0;i<n;i++){
           for(int j=0;j<m;j++){
               if(grid[i][j]=='1'){
                   solve(grid,i,j,n,m);
                   ans++;
               }
           }
       }
       return ans;
    }
};

/*
class Solution
{
    public:
    int numIslands(vector<vector<char>>& arr)
    {
        int n=arr.size();
        int m=arr[0].size();
        bool visited[n][m];memset(visited,false,sizeof(visited));
        queue <pair<int,int>> q;
        int _count=0;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(arr[i][j]=='1' && visited[i][j]==false){
                    _count++;
                    q.push(make_pair(i,j));visited[i][j]=true;
                    while(!q.empty()){
                        pair<int,int> temp=q.front();
                        q.pop();
                        int k=temp.first,l=temp.second;
                        if(k-1>=0 && arr[k-1][l]=='1' && !visited[k-1][l]){
                            q.push(make_pair(k-1,l));
                            visited[k-1][l]=true;
                        }
                        if(k+1<n && arr[k+1][l]=='1' && !visited[k+1][l]){
                            q.push(make_pair(k+1,l));
                            visited[k+1][l]=true;
                        }
                        if(l-1>=0 && arr[k][l-1]=='1' && !visited[k][l-1]){
                            q.push(make_pair(k,l-1));
                            visited[k][l-1]=true;
                        }
                        if(l+1<m && arr[k][l+1]=='1' && !visited[k][l+1]){
                            q.push(make_pair(k,l+1));
                            visited[k][l+1]=true;
                        }
                        if(k-1>=0 && l-1>=0 && arr[k-1][l-1]=='1' && !visited[k-1][l-1]){
                            q.push(make_pair(k-1,l-1));
                            visited[k-1][l-1]=true;
                        }
                        if(k-1>=0 && l+1<m && arr[k-1][l+1]=='1' && !visited[k-1][l+1]){
                            q.push(make_pair(k-1,l+1));
                            visited[k-1][l+1]=true;
                        }
                        if(k+1<n && l-1>=0 && arr[k+1][l-1]=='1' && !visited[k+1][l-1]){
                            q.push(make_pair(k+1,l-1));
                            visited[k+1][l-1]=true;
                        }
                        if(k+1<n && l+1<m && arr[k+1][l+1]=='1' && !visited[k+1][l+1]){
                            q.push(make_pair(k+1,l+1));
                            visited[k+1][l+1]=true;
                        }
                    }
                }
            }
        }
        return _count;
    }
};
*/