1128-number-of-equivalent-domino-pairs

DevGod

Elf Vtuber

Caution

DevGod needs to write an editorial for this problem!

js

/**
 * @param {number[][]} dominoes
 * @return {number}
 */
var numEquivDominoPairs = function(dominoes) {
    let myMap = new Map();
    let ans = 0;
    for(let dom of dominoes){
        let key = (1<<dom[0]) | (1<<dom[1]);
        ans += myMap.get(key)|0;
        myMap.set(key, (myMap.get(key)|0) +1);
    }

    return ans;
};