eBay Developer interview questions

1. Given an array of integers, every element appears twice except for one. Find that single one. 2. You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactly z litres using these two jugs. If z liters of water is measurable, you must have z liters of water contained within one or both buckets by the end. Operations allowed: Fill any of the jugs completely with water. Empty any of the jugs. Pour water from one jug into another till the other jug is completely full or the first jug itself is empty. 3. closure, performance , SEO

1st round: 1. How to uniquely identify the repeating strings from the array. 2. How to search in Skiplist 2nd round: 1. BinarySearch 2. How to write Customized Comparator 3. Anagrams 3rd round: Lunch with tech manager and find maximum sub array 4th round: 1. Binary Search in sorted matrix 2. Different ways of writing Singleton pattern 3. Resume go through 5th round: 1. How HashMap works 2. Get sum using minimum combination of numbers provided 6th round: 1. Singleton 2. Tree traversal 3. How to mirror the tree 4. Stack implementation 5. Queue using stack 6. Reverse the sentence