Package g2001_2100.s2001_number_of_pairs_of_interchangeable_rectangles

Class Solution

java.lang.Object
g2001_2100.s2001_number_of_pairs_of_interchangeable_rectangles.Solution
public class Solution extends Object
2001 - Number of Pairs of Interchangeable Rectangles.

Medium

You are given n rectangles represented by a 0-indexed 2D integer array rectangles, where rectangles[i] = [widthi, heighti] denotes the width and height of the ith rectangle.

Two rectangles i and j (i < j) are considered interchangeable if they have the same width-to-height ratio. More formally, two rectangles are interchangeable if widthi/heighti == widthj/heightj (using decimal division, not integer division).

Return the number of pairs of interchangeable rectangles in rectangles.

Example 1:

Input: rectangles = [[4,8],[3,6],[10,20],[15,30]]

Output: 6

Explanation: The following are the interchangeable pairs of rectangles by index (0-indexed):

  • Rectangle 0 with rectangle 1: 4/8 == 3/6.

  • Rectangle 0 with rectangle 2: 4/8 == 10/20.

  • Rectangle 0 with rectangle 3: 4/8 == 15/30.

  • Rectangle 1 with rectangle 2: 3/6 == 10/20.

  • Rectangle 1 with rectangle 3: 3/6 == 15/30.

  • Rectangle 2 with rectangle 3: 10/20 == 15/30.

Example 2:

Input: rectangles = [[4,5],[7,8]]

Output: 0

Explanation: There are no interchangeable pairs of rectangles.

Constraints:

  • n == rectangles.length
  • 1 <= n <= 105
  • rectangles[i].length == 2
  • 1 <= widthi, heighti <= 105

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • interchangeableRectangles

      public long interchangeableRectangles(int[][] rec)