JavaAlgorithms/Dynamic Programming/CoinChange.java

79 lines
2.5 KiB
Java

/**
*
* @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();
}
}