test.js

var _ = require('underscore');

// function sayHello() {
//   console.log('Hello, World');
// }

// _.times(5, sayHello);

// -- Start -- //
const employees_input = [
    '1,Richard,Engineering',
    '2,Erlich,HR',
    '3,Monica,Business',
    '4,Dinesh,Engineering',
    '6,Carla,Engineering',
    '9,Laurie,Directors'
];

const friendships_input = [
    '1,2',
    '1,3',
    '1,6',
    '2,4'
];

const expected_output = {
  1: [2,3,6],
  2: [1, 4],
  3: [1],
  4: [2],
  6: [1],
  9: [],
};

let final = {};

for(let item of employees_input){
    item = item.split(',');
    final[item[0]] = [];
  }


for(let connection of friendships_input){
    connection = connection.split(',');
    final[connection[0]].push(connection[1]);
    final[connection[1]].push(connection[0]);
  }

// console.log(final);


let final_two = {};

for(let department of employees_input){
  department = department.split(',');
  department = department[2];
  if(final_two.hasOwnProperty(department) === false){
    final_two[department] = {'employees': 1,          'employees_with_outside_friends': 0};
  } else {
    final_two[department].employees += 1;
  }
}


for(let department in final_two){
  for(let employee of employees_input){
    employee = employee.split(',');
    if(employee[2] === department){
      for(let friend of employees_input){
        friend = friend.split(',');
        if(employee[2] !== friend[2]){ 
          if(final[employee[0]].includes(friend[0])){
            final_two[department]['employees_with_outside_friends'] += 1;
          }
        }
      }
    }
  }
}



console.log(final_two);

const expected_output_2 = {
    'Engineering':{
        'employees':3,
        'count_of_employees_with_friends_in_other_departments':2
    },
    'HR':{
        'employees':1,
        'count_of_employees_with_friends_in_other_departments':1
    },
    'Business':{'employees':1, 'employees_with_outside_friends':1},
    'Directors':{'employees':1, 'employees_with_outside_friends':0}
}