#0271

Coin Change II

MediumDSA28 min20 XP

Problem

Given amount and coin denominations, return the number of combinations that sum to amount. Coin order does not matter.

Why This Matters

Coin Change II teaches the difference between combinations and permutations in DP loop order.

Function Signature

def coin_change_combinations(amount, coins):

Examples

Example 1

Inputamount = 5, coins = [1,2,5]

Output4

The combinations are 5, 2+2+1, 2+1+1+1, and five 1s.

Constraints

Return the exact requested value.
Handle edge cases cleanly.
Use the intended DSA pattern when brute force would scale poorly.

CodePython

def coin_change_combinations(amount, coins):
    """
    Input example: amount = 5, coins = [1,2,5]
    Return: 4
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return 0

def coin_change_combinations(amount, coins):
    """
    Input example: amount = 5, coins = [1,2,5]
    Return: 4
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return 0

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Four combinations

Inputamount = 5, coins = [1,2,5]

Expected4

Order does not create new combinations.

No combination

Inputamount = 3, coins = [2]

Expected0

You cannot make odd amount 3 using only coin 2.

Hidden Test Categories

amount zerocoin larger than amountmultiple coin sizes