Sparse Array

A two-dimensional array of values in which most elements are zero is called a sparse array. Because most elements have a value of zero, memory can be saved by storing only the non-zero values along with their row and column indexes.

Write a class SparseArrayEntry that keeps track of the row, column, and value (all int values) of an element in a sparse array. The constructor will take those three values as parameters. Write the methods getRow, getCol, getValue, and setValue for this class.

Then write a program SparseRandomWalker that tracks a random walker's location using an ArrayList of SparseArrayEntry objects.