Hi Guys,

I gave interview at Google sometime back and in telephonic round I was asked the below question:

Among the following sorting algorithms, which one is the most efficient:

1. Merge Sort 2. Insertion Sort 3. Quick Sort 4. Bubble Sort

It looks like this is an open ended question and I'm confused as some people say quick sort and some say merge sort even though quick sort runs in O(n^2) whereas merge sort runs in O(nlogn).

What should be the ideal answer for this question?

EDIT:
Other Questions:

1. Time complexity for HashTable
2. Time complexity for Self Balancing Binary Tree
3. Merge k sorted linked list(Coding)
4. Tell us the most challenging project you have worked upon and how did you tackle the same.