m0947.py

"""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 ith stone, return the largest possible number of stones that
can be removed.

Example 1:

* Input: stones = [[0,0],[0,1],[1,0],[1,2],[2,1],[2,2]]
* Output: 5
* Explanation: 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: stones = [[0,0],[0,2],[1,1],[2,0],[2,2]]
* Output: 3
* Explanation: 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: stones = [[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.
"""