JavaAlgorithms/DynamicProgramming/CoinChange.java
2020-10-24 10:23:28 +00:00

83 lines
2.4 KiB
Java

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();
}
}