Knapsack problem

The knapsack problem is like a game where you need to fill a knapsack (or a bag) with the most valuable stuff you can find. You have a list of items that are different sizes and have different values (like diamonds, gold coins, or teddy bears!). Your knapsack can only fit so much, so you need to be careful about what you pick. You want to get the most valuable items that fit! That's the knapsack problem.