The Orders

The orders have come in, and they're in a new list, orders. Each order is a record: who the customer is, which crop they want and how many pieces. Emma goes through the orders in the order they came in, and for each one:

• when she doesn't sell the crop at all (it has no price), the customer gets nothing;
• when there aren't enough pieces left in the barn, the customer gets nothing either: Emma doesn't sell half an order;
• otherwise, she takes the pieces out of the barn, and the customer pays for them.

Below the barn, print a line for each order, and then how many coins Emma earned:

Total: 200 coins
Hugo: 20 potatoes for 20 coins
Anna: 4 pumpkins for 60 coins
Grandpa Joe: 12 carrots for 24 coins
Tom: not enough pumpkins
Lily: no corn at the stall
Hugo: 10 carrots for 20 coins
Earned: 124 coins

Anna has taken 4 of the 6 pumpkins, so only 2 are left when Tom wants 3. Every order changes the barn for the orders after it.

A tip: a key that isn't in a dictionary gives nil, and you know from the lesson on conditions how to check for that.