Add Customer class for food item ordering

Create Customer2.java

Create Customer.java

Create Tester.java

Update basic.java

Add basic Java program demonstrating operators

Add files via upload

Create 1758. Minimum Changes To Make Alternating Binary String

Create LeetCode 136 single number.java

Create LeetCode 137 single number.java

Add solution for defanging an IP address

Create 13. Roman to Integer

Create 3637. Trionic Array I

Create 3217. Delete Nodes From Linked List Present in Array

Create 3289. The Two Sneaky Numbers of Digitville