Reverse Spiral Traversal of Sparse Matrix

Traverse a Sparse matrix in reverse spiral order. The Sparse matrix is represented in the form of a triplet $[row index, column index, value]$ following row-major order. The starting point for traversal, i.e. the row index and the column index is given as an input. The sequence of directions to be followed from the given starting point is $Down$ $(1)$, $Right$ $(2)$, $Up$ $(3)$, and then $Left$ $(