C++ Decrypt Polybiuus Square

Implement function polybiusSquare(char grid[SIZE][SIZE], string key, string original). Decrypt string original using string key and the Polybius Square.

https://en.wikipedia.org/wiki/Polybius_square

Functions already implemented:

- string mixKey(string key): returns a string of characters with the key at the beginning, followed by non-repeating alphanumerics

- fillGrid(char grid[SIZE][SIZE], string content): fills the 6x6 grid with string content

- string findInGrid(char c, char grid[SIZE][SIZE]): returns a string of numbers corresponding to to character c in Polybius Square

- int charToInt(char original): accepts char original and returns it as an integer

Sample Output:

char grid[SIZE][SIZE];

cout << polybiusSquare(grid, "183", "11110533 000102 1533 341411 04113334", false) << endl;

prints: "EECS 183 IS THE BEST"