Create CoinChange.java

Author: varunu28

Dynamic Programming/CoinChange.java

@@ -0,0 +1,52 @@
+/**
+ *
+ * @author Varun Upadhyay (https://github.com/varunu28)
+ *
+ */
+
+public class CoinChange {
+
+    // Driver Program
+    public static void main(String[] args) {
+
+        int amount = 12;
+        int[] coins = {1, 2, 5};
+
+        System.out.println("Number of combinations of getting change for " + amount + " is: " + change(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++) {
+                if (i>=coin) {
+                    combinations[i] += combinations[i-coin];
+                }
+            }
+            // Uncomment the below line to see the state of combinations for each coin
+            // printAmount(combinations);
+        }
+
+        return combinations[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();
+    }
+
+}