interview-coding-practice.js

// 1) Simple cache class with limited size
const c = new Cache(3); // 3 is maximum length of cache
// add(key, value), key any type, value any type;
c.add('one', 1);
c.add('two', { a: 2 });
c.add('three', '3');
c.get('one'); // -> 1
c.add('four', 4);
c.get('one'); // -> undefined

// 2) Restore gaps in the sequence
const restore = sequence([1, 5, 7, 9, 13]);
restore(); // -> [1, 3, 5, 7, 9, 11, 13]

// 3) Data service
const dataService = new DataService();
sortService.load(data);
sortService.top(n, field ); // n: number of items to return, field: name of field to sort by


// 4) loadService
// 5) sortService

// 6) Make this work
var a = (5).plus(3).minus(6);

// 7) You have a function rand5() that generates a random integer from 1 to 5. 
//    Use it to write a function rand7() that generates a random integer from 1 to 7.

// 8) We want to fill this array with numbers from the counter. We then want to halve 
// each number in the array, and then filter only integer results.

const getNum = () => counter.step();
const halve = x => x / 2;
const isInt = x => Math.floor(x) === x;

// naive solution
bigArray
  .map(getNum)
  .map(halve)
  .filter(isInt);

// performant solution
bigArray.reduce(newArr => {
  const x = getNum();
  const hlv = halve(x);
  if (isInt(hlv)) {
    newArr.push(hlv);
  }
  return newArr;
}, []);




// N) validate code
(function() {
   var a = b = 5;
})();

console.log(b);


function test() {
   console.log(a);
   console.log(foo());
   
   var a = 1;
   function foo() {
      return 2;
   }
}

test();


//1. [-1, null, 2, 'five', 1].sort(); // => [1, 2, -1, null, 'five']
//2. sort all odd/even positions of array
//3. data struture add O(1), get O(1), remove 0(1), reset 0(1)
//4. point on surface
//5. App to generate pin code with designed complexity
//6. The longest english word, you can display on 7-segment display. /gkmqvwxz/