The long run of a coin

You will toss a coin 500 times in a program, keep the share of heads after every toss, and draw how that share moves. Then you see how close the last share comes to 0.5.

The idea. The share of heads jumps about in a short run and settles near the probability, 0.5, in a long run.

Your tasks.

1. In toss, return 1 for heads with probability 0.5, and 0 otherwise.
2. In the loop, add the share of heads so far to shares after each toss.
3. Set last_gap to how far the last share is from 0.5.