Challenge: Create an Amount

Problem statement

Given an array of coins, write a function to compute the number of ways you can make that amount using those coins.

Note: There is an unlimited number of each coin type available.

Input

• an amount

• an array, coins, containing different coins (in cents $¢$)

Output

• The number of ways to get the amount using the coins available

Sample input

amount = 4
coins = [1,2,3]

Here’s the amount all the coin values are given in cents ($¢$).

Sample output

4

How did we get this answer? Let’s look at the different ways:

• $1$,$1$,$1$,$1$

• $1$,$1$,$2$

• $1$,$3$

• $2$,$2$

All of the above coin combinations sum to the amount given.