• Home
• com.github.javadev
• leetcode-in-java
• 1.17
• source code
• readme.md

×

Project download

Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $

You can buy this project and download/modify it how often you want.

g1101_1200.s1128_number_of_equivalent_domino_pairs.readme.md Maven / Gradle / Ivy

1128\. Number of Equivalent Domino Pairs

Easy

Given a list of `dominoes`, `dominoes[i] = [a, b]` is **equivalent to** `dominoes[j] = [c, d]` if and only if either (`a == c` and `b == d`), or (`a == d` and `b == c`) - that is, one domino can be rotated to be equal to another domino.

Return _the number of pairs_ `(i, j)` _for which_ `0 <= i < j < dominoes.length`_, and_ `dominoes[i]` _is **equivalent to**_ `dominoes[j]`.

**Example 1:**

**Input:** dominoes = [[1,2],[2,1],[3,4],[5,6]]

**Output:** 1

**Example 2:**

**Input:** dominoes = [[1,2],[1,2],[1,1],[1,2],[2,2]]

**Output:** 3

**Constraints:**

*   1 <= dominoes.length <= 4 * 104
*   `dominoes[i].length == 2`
*   `1 <= dominoes[i][j] <= 9`