MaxMin.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', function() {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

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

// Complete the maxMin function below.
function maxMin(k, arr) {

  arr = arr.sort((a, b) => a - b)
  let diff = Math.max(...arr)
  for (let i = 0; i + k <= arr.length; i++) {
    let spl = arr.slice(i, i + k)
    if (spl[spl.length - 1] - spl[0] < diff  ) {
      diff = spl[spl.length - 1] - spl[0]
    }
  }
  return diff
}

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

    const n = parseInt(readLine(), 10);

    const k = parseInt(readLine(), 10);

    let arr = [];

    for (let i = 0; i < n; i++) {
        const arrItem = parseInt(readLine(), 10);
        arr.push(arrItem);
    }

    const result = maxMin(k, arr);

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

    ws.end();
}