Consider a 2-dimensional spreadsheet a rectangular grid of cells, each of which holds an anarbitrary string of characters, or an empty string if the value of the cell has not yet been dened. Each cell is identied by 2 non-negative integer values, identifying a specic row and column. Dene a C99 data structure to dene an instance of the 2-dimensional spreadsheet.Next, dene and implement three C99 functions: one to return a pointer to allocated memory suitable for storing and managing the

spreadsheet, one to swap the contents of two indicated columns in a spreadsheet, and one to completely deallocate all memory allocated to a spreadsheet.