Iterative logarithmic exponentiation
问题 I bombed an interview (phone screen with collabedit) recently. Here is the question: Write an interative O(lg n) algorithm for finding the power of x^y (x is a double, y>0 is an int). I first did the recursive divide and conquer one and tried to convert it to iterative... and I couldn't :S Is there a method to convert recursion to iterative (it is easy for tail recursion, but how about recursive functions with two possible recursive calls which depend on conditions to decide which call will