Write and test a function that creates Pascal's Triangle in the square matrix that is passed to it. For example, if the two-dimensional array a and the integer 4 were passed to the function, then it would load the following into a:
1 0 0 0 0
1 1 0 0 0
1 2 1 0 0
1 3 3 1 0
1 4 6 4 1