- What I thought was naive is what most ppl did.
- Try to give changes with bigger values.
- Use an array to store how many bills we have for each value.
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
$20 bill. You must provide the correct change to each customer so that the net transaction is that the customer pays
Note that you don’t have any change in hand at first.
Given an integer array bills where bills[i] is the bill the ith customer pays, return true if you can provide every customer with correct change, or false otherwise.
Input: bills = [5,5,5,10,20]