1. Using induction, prove that Insertion Sort will always produce a sorted array
2. Write an Insertion Sort algorithm for integer key values. However, here's the catch: The input is a stack (not an array), and the only variables that your algorithm may use are a fixed number of integers and a fixed number of stacks. The algorithm should return a stack containing the records in sorted order (with the least value being at the top of the stack). Your algorithm should be Θ(n 2 ) in the worst case.