Coin change ways
Given an integer amount and a list of distinct positive coin denominations (unlimited supply of each), return the number of distinct combinations of coins that sum to exactly amount. Combinations are unordered, so {1,2} and {2,1} count once. Return 0 if it cannot be made; amount may be 0 (one way: use no coins).
Implement
coin_combinations(amount: int, coins: list[int]) → intExamples
in
[5,[1,2,5]]out4What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 20 min
solution.py
InputExpectedGot
[5,[1,2,5]]4not run yetsample