An algorithm to equally distribute students to the number of available teachers.

group.js

/**
 * Group.js
 * An algorithm to equally distribute students to the number of available teachers.
 * Complexity is O(n).
 *
 * @input Arrays of teachers and students.
 * @output Array of objects of grouped students and teachers.
 *
 * Run in Node (CommonJS)
 * How to run: Clone or copy the gist, then do node ./group.js
 */

/**
 * Prepare our data.
 */
const teachers = require('./teachers');
const students = require('./students');

/**
 * Shuffles a list with Fischer Yates Algorithm.
 * Complexity: O(n).
 *
 * @param  {...number} list
 */
function fischerYates(...list) {
  for (let i = 0; i < list.length; i += 1) {
    // 1. Get a random number between zero and the max array length, inclusive.
    const randomNumber = Math.floor(Math.random() * list.length);

    // 2. Shuffle.
    const placeholder = list[i];
    list[i] = list[randomNumber];
    list[randomNumber] = placeholder;
  }
}

/**
 * Driver code.
 */
function main() {
  // 0. Prepare a variable to store the results of the operation.
  const results = [];

  // 1. Shuffle first.
  fischerYates(students);
  fischerYates(teachers);

  // 2. Assign each teachers to a new array.
  teachers.forEach((teacher) => {
    results.push({
      teacher,
      students: [],
    });
  });

  // 3. Assign each students to the 'results' array, pop them.
  // Pop an array with a random index.
  // Complexity: O(n).
  let counter = 0;
  while (students.length > 0) {
    const randomIndex = Math.floor(Math.random() * students.length);
    results[counter].students.push(students[randomIndex]);
    students.splice(randomIndex, 1);

    if (counter === teachers.length - 1) {
      counter = 0;
    } else {
      counter += 1;
    }
  }

  // Print the results.
  for (let i = 0; i < results.length; i += 1) {
    console.log(results[i]);
  }
}

if (require.main === module) {
  main();
}

students.js

module.exports = [
  {
    id: 'S1',
    name: 'Thomas Andreas',
  },
  {
    id: 'S2',
    name: 'Bernardus Gery Santoso',
  },
  {
    id: 'S3',
    name: 'Kharansyah Tawaddhu Shalam',
  },
  {
    id: 'S4',
    name: 'Sinzie Winata',
  },
  {
    id: 'S5',
    name: 'Attar Kusuma Pratiwa',
  },
  {
    id: 'S6',
    name: 'Farrel Irsyad Fanny',
  },
  {
    id: 'S7',
    name: 'Mochamad Rizky Zaldi',
  },
  {
    id: 'S8',
    name: 'Lucky Benedict',
  },
  {
    id: 'S9',
    name: 'Muhammad Faisal Farhan',
  },
  {
    id: 'S10',
    name: 'Deka Primatio Deandra',
  },
  {
    id: 'S11',
    name: 'Gregorius Haryanto Setiadi',
  },
  {
    id: 'S12',
    name: 'Muhammad Faiz Ramdhani',
  },
  {
    id: 'S13',
    name: 'Fadla Ichsan',
  },
  {
    id: 'S14',
    name: 'Raul Andrian',
  },
];

teachers.js

module.exports = [
  {
    id: 'T1',
    name: 'Mr. Krabs',
  },
  {
    id: 'T2',
    name: 'Spongebob Squarepants',
  },
  {
    id: 'T3',
    name: 'Squidward Tentacles',
  },
];