Consider a table of the triangular shape shown in Figure 9.7, where the columnsare indexed from −n to n and the rows from 0 to n.

Figure 9.7. A table symmetrically triangular around 0
(a) Devise an index function that maps a table of this shape into a sequentialarray.
(b) Write a function that will generate an access array for finding the first entryof each row of a table of this shape within the contiguous array.
(c) Write a function that will reflect the table from left to right. The entriesin column 0 (the central column) remain unchanged, those in columns −1and 1 are swapped, and so on.

Implement the method described in the text that uses an access array to storea lower triangular table, as applied in the following projects.