[Leetcode]860. Lemonade Change
📄 Description
At a lemonade stand, each lemonade costs $5
. Customers are standing in a queue to buy from you and order one at a time (in the order specified by bills). Each customer will only buy one lemonade and pay with either a $5
, $10
, or $20
bill. You must provide the correct change to each customer so that the net transaction is that the customer pays $5
.
Note that you do not have any change in hand at first.
Given an integer array bills
where bills[i]
is the bill the customer pays, return true
if you can provide every customer with the correct change, or false
otherwise.
Example 1:
Input: bills = [5,5,5,10,20]
Output: true
Explanation:
From the first 3 customers, we collect three $5 bills in order.
From the fourth customer, we collect a $10 bill and give back a $5.
From the fifth customer, we give a $10 bill and a $5 bill.
Since all customers got correct change, we output true.
Example 2:
Input: bills = [5,5,10,10,20]
Output: false
Explanation:
From the first two customers in order, we collect two $5 bills.
For the next two customers in order, we collect a $10 bill and give back a $5 bill.
For the last customer, we can not give the change of $15 back because we only have two $10 bills.
Since not every customer received the correct change, the answer is false.
Constraints:
1 <= bills.length <= 105
bills[i]
is either5
,10
, or20
.
🔨 My Solution
문제 해결 포인트!
$20
을 받았을 때 줄 수 있는 거스름돈 종류가 다음 두 가지이다.
1.$5
한 개 &$10
한 개
2.$5
세 개- 위 두 가지 방법 중 어떤 방법을 선택하는 것이 효율적인가? 를 생각해볼 것.
💻 My Submission
class Solution:
def lemonadeChange(self, bills: List[int]) -> bool:
change=0
bill_dict={5:0,
10:0}
for i in range(len(bills)):
if bills[i]==5:
bill_dict[bills[i]]+=1
elif bills[i]==10:
if bill_dict[5]<1: return False
bill_dict[bills[i]]+=1
bill_dict[5]-=1
elif bills[i]==20:
# (5,10) or (5,5,5)
if bill_dict[5]>0 and bill_dict[10]>0:
bill_dict[10]-=1
bill_dict[5]-=1
elif bill_dict[5]>=3:
bill_dict[5]-=3
else: return False
return True
💊 Clean Code
def lemonadeChange(self, bills):
five = ten = 0
for i in bills:
if i == 5: five += 1
elif i == 10: five, ten = five - 1, ten + 1
elif ten > 0: five, ten = five - 1, ten - 1
else: five -= 3
if five < 0: return False
return True
💡 What I learned
- 어떤 자료구조에 담을지 잘 판단하기
- 어떻게 하면 readable 한 코드가 될 수 있을지 고민하기
- 중복되는 조건문이 없도록 하기
References
Author And Source
이 문제에 관하여([Leetcode]860. Lemonade Change), 우리는 이곳에서 더 많은 자료를 발견하고 링크를 클릭하여 보았다 https://velog.io/@limelimejiwon/Leetcode860.-Lemonade-Change저자 귀속: 원작자 정보가 원작자 URL에 포함되어 있으며 저작권은 원작자 소유입니다.
우수한 개발자 콘텐츠 발견에 전념 (Collection and Share based on the CC Protocol.)