Most Stones Removed with Same Row or Column

On a 2D plane, we place n stones at some integer coordinate points. Each coordinate point may have at most one stone.

A stone can be removed if it shares either the same row or the same column as another stone that has not been removed.

Given an array stones of length n where stones[i] = [xi, yi] represents the location of the i^th stone, return the largest possible number of stones that can be removed.

Input Format:

First parameter: integer n

Second parameter: An array stones of size n x 2.

Output format:

Return the number.

Example 1:

Input:
6 2
0 0
0 1
1 0
1 2
2 1
2 2
Output: 
5
Explanation: 6 2 represents the size of the array stones
One way to remove 5 stones is as follows:
1. Remove stone [2,2] because it shares the same row as [2,1].
2. Remove stone [2,1] because it shares the same column as [0,1].
3. Remove stone [1,2] because it shares the same row as [1,0].
4. Remove stone [1,0] because it shares the same column as [0,0].
5. Remove stone [0,1] because it shares the same row as [0,0].
Stone [0,0] cannot be removed since it does not share a row/column with another stone still on the plane.

Example 2:

Input:
5 2
0 0
0 2
1 1
2 0
2 2
Output: 
3
Explanation: 5 2 represents the size of the array stones
One way to make 3 moves is as follows:
1. Remove stone [2,2] because it shares the same row as [2,0].
2. Remove stone [2,0] because it shares the same column as [0,0].
3. Remove stone [0,2] because it shares the same row as [0,0].
Stones [0,0] and [1,1] cannot be removed since they do not share a row/column with another stone still on the plane.

Example 3:

Input:
1 2
0 0
Output: 
0
Explanation: [0,0] is the only stone on the plane, so you cannot remove it.

Constraints:

• 1 <= stones.length <= 1000
• 0 <= xi, yi <= 104
• No two stones are at the same coordinate point.
• Expected Time Complexity: O(n)
• Expected Space Complexity: O(n)