Rat in a Maze Problem - I

//{ Driver Code Starts
// Initial template for C++

#include <bits/stdc++.h>
using namespace std;


// } Driver Code Ends
// User function template for C++

class Solution{
    public:
    vector<string> ans;
    bool isSafe(int newx,int newy,vector<vector<int>> &m,vector<vector<bool>> &vis,int n)
    {
        if((newx>=0 && newx<n) && (newy>=0 && newy<n) && vis[newx][newy]!=1 && m[newx][newy]==1)
        {
            return true;
        }
        return false;

}
    void solve(int x,int y,vector<vector<int>> &m, int n,vector<vector<bool>> &vis,string path)
    {
        if(x==n-1 && y==n-1)
        {
            ans.push_back(path);
            return;
        }
        vis[x][y]=1;
        if(isSafe(x+1,y,m,vis,n))
        {
            solve(x+1,y,m,n,vis,path+'D');
        }

        if(isSafe(x,y-1,m,vis,n))
        {
            solve(x,y-1,m,n,vis,path+'L');
        }

        if(isSafe(x,y+1,m,vis,n))
        {
            solve(x,y+1,m,n,vis,path+'R');
        }

        if(isSafe(x-1,y,m,vis,n))
        {
            solve(x-1,y,m,n,vis,path+'U');
        }
        vis[x][y]=0;
    }

    vector<string> findPath(vector<vector<int>> &m, int n) {
        //   vector<string> ans;
          vector<vector<bool>> vis(n,vector<bool> (n,0));
          string path="";
          if(m[0][0]==0)
          {
              return ans;
          }
          solve(0,0,m,n,vis,path);
          return ans;
    }
};




//{ Driver Code Starts.

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        vector<vector<int>> m(n, vector<int> (n,0));
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                cin >> m[i][j];
            }
        }
        Solution obj;
        vector<string> result = obj.findPath(m, n);
        sort(result.begin(), result.end());
        if (result.size() == 0)
            cout << -1;
        else
            for (int i = 0; i < result.size(); i++) cout << result[i] << " ";
        cout << endl;
    }
    return 0;
}
// } Driver Code Ends