package DynamicProgramming;

/** @author Varun Upadhyay (https://github.com/varunu28) */
public class CoinChange {

 // Driver Program
 public static void main(String[] args) {

 int amount = 12;
 int[] coins = {2, 4, 5};

 System.out.println(
 "Number of combinations of getting change for " + amount + " is: " + change(coins, amount));
 System.out.println(
 "Minimum number of coins required for amount :"
 + amount
 + " is: "
 + minimumCoins(coins, amount));
 }

 /**
 * This method finds the number of combinations of getting change for a given amount and change
 * coins
 *
 * @param coins The list of coins
 * @param amount The amount for which we need to find the change Finds the number of combinations
 * of change
 */
 public static int change(int[] coins, int amount) {

 int[] combinations = new int[amount + 1];
 combinations[0] = 1;

 for (int coin : coins) {
 for (int i = coin; i < amount + 1; i++) {
 combinations[i] += combinations[i - coin];
 }
 // Uncomment the below line to see the state of combinations for each coin
 // printAmount(combinations);
 }

 return combinations[amount];
 }

 /**
 * This method finds the minimum number of coins needed for a given amount.
 *
 * @param coins The list of coins
 * @param amount The amount for which we need to find the minimum number of coins. Finds the the
 * minimum number of coins that make a given value.
 */
 public static int minimumCoins(int[] coins, int amount) {
 // minimumCoins[i] will store the minimum coins needed for amount i
 int[] minimumCoins = new int[amount + 1];

 minimumCoins[0] = 0;

 for (int i = 1; i <= amount; i++) {
 minimumCoins[i] = Integer.MAX_VALUE;
 }
 for (int i = 1; i <= amount; i++) {
 for (int coin : coins) {
 if (coin <= i) {
 int sub_res = minimumCoins[i - coin];
 if (sub_res != Integer.MAX_VALUE && sub_res + 1 < minimumCoins[i])
 minimumCoins[i] = sub_res + 1;
 }
 }
 }
 // Uncomment the below line to see the state of combinations for each coin
 // printAmount(minimumCoins);
 return minimumCoins[amount];
 }

 // A basic print method which prints all the contents of the array
 public static void printAmount(int[] arr) {
 for (int i = 0; i < arr.length; i++) {
 System.out.print(arr[i] + " ");
 }
 System.out.println();
 }
}