React

by slikts

React

const count = xs => xs.reduce((a, x) => a.set(x, 1 + (a.get(x) || 0)), new Map())
const pairs = xs => [...count(xs)].filter(([, n]) => n > 2).map(([x, n]))

console.log(pairs([1, 1, 3, 4, 5, 3, 2, 3, 1, 1, 1]))