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 Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
long	interchangeableRectangles(int[][] rec)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

interchangeableRectangles

public long interchangeableRectangles(int[][] rec)