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coin-change.py
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coin-change.py
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import heapq
class Solution:
def coinChange(self, coins, amount):
dp = [-1] * amount + [0]
left = amount
while left > 0:
if dp[left] == -1:
left -= 1
continue
for coin in coins:
if left >= coin:
if dp[left - coin] > 0:
dp[left - coin] = min(dp[left] + 1, dp[left - coin])
else:
dp[left - coin] = dp[left] + 1
left -= 1
return dp[0]
def coinChangeTry2(self, coins, amount):
dp = [0] + [-1] * amount
dp_nonempty = [0]
dp_nonempty_set = set([0])
while len(dp_nonempty):
total = heapq.heappop(dp_nonempty)
for coin in coins:
total_next = total + coin
if total_next <= amount:
if dp[total_next] > 0:
dp[total_next] = min(dp[total] + 1, dp[total_next])
else:
dp[total_next] = dp[total] + 1
if total_next not in dp_nonempty_set:
heapq.heappush(dp_nonempty, total_next)
dp_nonempty_set.add(total_next)
return dp[amount]
class TestSolution:
def setup(self):
self.sol = Solution()
def test_empty1(self):
assert self.sol.coinChange([], 11) == -1
def test_empty2(self):
assert self.sol.coinChange([], 0) == 0
def test_custom1(self):
assert self.sol.coinChange([1], 1) == 1
def test_custom2(self):
assert self.sol.coinChange([2], 3) == -1
def test_custom3(self):
assert self.sol.coinChange([1, 2, 5], 11) == 3