#0168

Coin Change Minimum Coins

MediumDSA25 min20 XP

Problem

Given coin denominations and an amount, return the minimum number of coins needed. Return -1 if impossible.

Why This Matters

Coin change teaches how DP reuses smaller answers instead of recursively trying every combination.

Function Signature

def coin_change(coins, amount):

Examples

Example 1

Inputcoins = [1, 2, 5], amount = 11

Output3

11 can be made with 5 + 5 + 1.

Constraints

Return the exact requested output.
Handle ordinary edge cases.
Prefer simple, interview-readable code.

CodePython

def coin_change(coins, amount):
    """
    Input example: coins = [1, 2, 5], amount = 11
    Return: 3
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return -1

def coin_change(coins, amount):
    """
    Input example: coins = [1, 2, 5], amount = 11
    Return: 3
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return -1

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputcoins = [1, 2, 5], amount = 11

Expected3

11 can be made with 5 + 5 + 1.

Hidden Test Categories

empty or minimal inputduplicates or tieslarger input