[Interview Questions] sorting of K-order Arrays

I saw an interview question on the Internet and thought it was a good idea. I 'd like to add it to my favorites.

What is a K-order array first?

Arrays with such features:

The I-th element is located between [I-K, I + k] After sorting.

K-order

Requirement: The test algorithm sorts a K-order array.

 

Solution:

According to the K-order array feature, there are obviously the following subsequences:

X [0], X [k + 1], X [2 (k + 1)], X [3 (k + 1)] ......

X [1], X [k + 1 + 1], X [2 (k + 1) + 1], X [3 (k + 1) + 1] ......

........................

X [K], X [k + 1 + K], X [2 (k + 1) + K], X [3 (k + 1) + k] ......

This k + 1 sub-sequence has been sorted, and the rest of the task isMerge

There are two methods:

Method 1: For a normal merge, the complexity is O (NK), which is the same as merging two arrays)

Method 2: Use the loser tree to merge the time when an element requires a logk and the time when n elements require O (nlogk ).