Unique Paths

62. Unique Paths

Solution 1

1. For each box, there are two possible directions to approach it (from left or from top).
2. Sum the two approaches together for the final result.
   Space Complexity: O(m * n)

   Solution 2

3. For each box, there are two possible directions to approach it (from left or from top).
4. We store the number of unique paths for the last row we are traversing, s.t. we do not have to store the information of previous rows.
   Space Complexity: O(n)