Minimum coin change

The second example shown in this chapter presents a greedy algorithm to solve the minimum coin change problem, for finding the minimum number of coins to receive the amount specified as the input.

Figure 9.2 – Illustration of denominations in the case of the euro currency

For example, for the coin system consisting of 1, 2, 5, 10, 20, 50, 100, 200, and 500 denominations, if you want to get a value of 158, you need to pick 5 coins, namely 100, 50, 5, 2, and 1. The greedy approach is very simple because you just pick the largest possible denomination not greater than the remaining amount. You perform this operation until the remaining amount is equal to 0. As you see, the algorithm does not care about the overall solution and tries to choose the best solution at each step.

The C#-based implementation is shown here:

int[] den = [1, 2, 5, 10, 20, 50, 100, 200, 500];
List<int> coins = GetCoins(158);
coins.ForEach(Console...