#860

Lemonade Change

pupil · 385 · lc easy +24 · verified · 58.9% accepted · 3,390 likes · top 56%

Description

You run a lemonade stand where each cup costs $5. Customers line up and pay with $5, $10, or $20 bills, one at a time in the order given by bills. You must give each customer exact change; you start with no cash.

Given an integer array bills where bills[i] is the payment of the i^th customer, return true if you can provide correct change to every customer, 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.

Code

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class Solution:
    def lemonadeChange(self, bills: List[int]) -> bool:

class Solution:
    def lemonadeChange(self, bills: List[int]) -> bool: