Problems
TODO: CTCI 16.23 – https://www.quora.com/How-do-you-design-a-rand7-function-using-a-rand5-function, https://stackoverflow.com/questions/137783/expand-a-random-range-from-1-5-to-1-7
TODO: CTCI 16.23 – https://www.quora.com/How-do-you-design-a-rand7-function-using-a-rand5-function, https://stackoverflow.com/questions/137783/expand-a-random-range-from-1-5-to-1-7