beautiful-triplets.js

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

function readLine() {
    return inputString[currentLine++];
}

// Complete the beautifulTriplets function below.
function beautifulTriplets(d, arr) {

    let c = 0;
    for (var i = 0; i < arr.length; i++) {
        for (var j = i + 1; j < arr.length; j++) {
            if (Math.abs(arr[i] - arr[j]) === d) {
                for (var k = j + 1; k < arr.length; k++) {
                    if (Math.abs(arr[j]- arr[k]) === d) {
                        c++;
                    }
                }
            }
        }
    }
    return c;
}

function main() {
    const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

    const nd = readLine().split(' ');

    const n = parseInt(nd[0], 10);

    const d = parseInt(nd[1], 10);

    const arr = readLine().split(' ').map(arrTemp => parseInt(arrTemp, 10));

    let result = beautifulTriplets(d, arr);

    ws.write(result + "\n");

    ws.end();
}