Package g0801_0900.s0860_lemonade_change

Class Solution

  • public class Solution
extends Object
    860 - Lemonade Change.

    Easy

    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 ith 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 either 5, 10, or 20.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • lemonadeChange

        public boolean lemonadeChange​(int[] bills)