function beautifulTriplets(d, arr) {

let hash = {}
let counter = 0
for (const n of arr) {
    hash[n] = !hash[n] ? 1 : hash[n] + 1;
}

for (const k in hash) {
    const sec = Number(k) + d;
    const third = sec + d;

    if (hash[sec] && hash[third]) counter += Math.max(hash[k], hash[sec], hash[third])
}
return counter

}