 Rat in a Maze Problem - I
Medium Accuracy: 37.73% Submissions: 32089 Points: 4

Consider a rat placed at (0, 0) in a square matrix of order N*N. It has to reach the destination at (N-1, N-1). Find all possible paths that the rat can take to reach from source to destination. The directions in which the rat can move are 'U'(up), 'D'(down), 'L' (left), 'R' (right). Value 0 at a cell in the matrix represents that it is blocked and cannot be crossed while value 1 at a cell in the matrix represents that it can be traveled through.

Example 1:

Input: N = 4, m[][] = {{1, 0, 0, 0},
{1, 1, 0, 1},
{1, 1, 0, 0},
{0, 1, 1, 1}}
Output: DDRDRR DRDDRR
Explanation: The rat can reach the
destination at (3, 3) from (0, 0) by two
paths ie DRDDRR and DDRDRR when printed
in sorted order we get DDRDRR DRDDRR.
Example 2:
Input: N = 2, m[][] = {{1, 0},
{1, 0}}
Output: -1
Explanation: No path exits

You don't need to read input or print anything. Complete the function printPath() which takes N and 2d array m[][] as input parameters and returns a sorted list of paths.

Note:  In case of no path, return an empty list. The driver will output -1 automatically.

Expected Time Complexity: O((N2)4).
Expected Auxiliary Space: O(L*X), L = length of the path, X = number of paths.

Constraints:
2 ≤ N ≤ 5
0 ≤ m[i][j] ≤ 1 