Algorithm Notes
Summary: Coin Change — notes not yet curated.
Time: Estimate via loops/recurrences; common classes: O(1), O(log n), O(n), O(n log n), O(n^2)
Space: Count auxiliary structures and recursion depth.
Tip: See the Big-O Guide for how to derive bounds and compare trade-offs.
Big-O Guide
Source
"""
Coin Change
TODO: Add problem description
"""
from src.interview_workbook.leetcode._registry import register_problem
from src.interview_workbook.leetcode._types import Category, Difficulty
class Solution:
def solve(self, *args) -> int:
"""Return the fewest coins needed to make up the amount or -1 if not possible."""
if len(args) != 2:
return -1
coins, amount = args
dp = [amount + 1] * (amount + 1)
dp[0] = 0
for a in range(1, amount + 1):
for c in coins:
if a - c >= 0:
dp[a] = min(dp[a], dp[a - c] + 1)
return dp[amount] if dp[amount] != amount + 1 else -1
def demo():
"""Run a demo for the Coin Change problem."""
solver = Solution()
coins = [1, 2, 5]
amount = 11
result = solver.solve(coins, amount)
return str(result)
register_problem(
id=322,
slug="coin_change",
title="Coin Change",
category=Category.DP_1D,
difficulty=Difficulty.MEDIUM,
tags=["array", "dynamic_programming", "bfs"],
url="https://leetcode.com/problems/coin-change/",
notes="",
)