Find K nearest Points to Point P in 2-dimensional plane

Question

Source: AMAZON INTERVIEW QUESTION

Given a point P and other N points in two dimensional space, find K points

Answer 1

What is wrong with below approach ?

1) Calculate distance from given point to other points.

2) Store the distance and index of that point to TreeMap map

3) Select top K elements from map. It's values will give index of Point element from points array.

The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time,