Write a program in C to play a game of Sudoku with the user. The goal of the game is to fill in missing numbers in an 9x9 array. Each number in the set [1-9] must be found in every row, every column, and every 3x3 block in the array.

The user should be able to set entries in the game board by providing input in the form row,column,value to solve a specific square, or enter -1 to exit the program.

When the user has filled in all blank spaces in the game board, the program should determine if the current board is a valid solution and inform the user accordingly. Note that a Sudoku board could have multiple solutions! The solution provided with the initial puzzle may not be the only valid solution the user could provide. Thus, you should not simply compare the user's input to the original solution. Instead, you need to test the user's solution against the Sudoku rules previously described.

Use a two-dimensional array of integers to store the current state of the puzzle. In this array, values of 1-9 represent user input, and a value of -1 represents a space with no current value. As the game is played, update this array based on user input.

You must use dynamic memory allocation to store this array. Remember to release dynamic memory before exiting! How can this be accomplished? In C, a two-dimensional array is simply an array of arrays, and you can allocate a single-dimensional array using malloc() or calloc().