Binary Search on an Ascending Array

Read an integer N, then N integers in ascending order into an array, then a key. Verify the order first: if any value is smaller than the one before it, print array is not in ascending order and return 1. Then search with a lo, hi, mid window, computing mid as lo + (hi - lo) / 2 and moving lo to mid + 1 or hi to mid - 1, and print key 23 found at index 5 with the zero-based index, or key 7 not found. N must be between 1 and 100; otherwise print N must be between 1 and 100 and return 1. If N, any value, or the key cannot be read, print invalid input and return 1.