7.11) Exercise 18 - While Loop

1. Write a program that asks you if it can have an ice-cream and waits for your answer. The program then nags you by saying 'Oh please, say yes!' until you say 'yes'.
2. Write a program which prints out different permutations of matches between tennis players A, B, C, D

Hint : a simple way of listing the permutation of the game is:

A-B A-C A-D
B-C B-D
C-D

Solution: exercise_tournament.py