# SingleNumber

Problem Statement Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without extra memory?
Thought Process My initial conclusion was that no, you couldn’t. Since there’s not a range for the possible numbers in the array and the array isn’t already sorted, you can solve in linear time if you used an object to store counts, but you need that extra storage or sorting is O(n log n).