Write a program that, given a small positive even integer from standard input, calculates the probability that flipping that many coins will result in half as many heads.
For example, given 2 coins the possible outcomes are:
HH HT TH TT
where H and T are heads and tails. There are 2 outcomes (
TH) that are half as many heads as the number of coins. There are a total of 4 outcomes, so the probability is 2/4 = 0.5.
This is simpler than it looks.
2 -> 0.5 4 -> 0.375 6 -> 0.3125 8 -> 0.2734375