array_methods.ts

//

// O(1) Time Complexity, O(1) Space complexity
const push = (array: number[], num: number): number[] => {
  array[array.length] = num;
  return array;
};

// O(1) Time Complexity, O(1) Space complexity
const pop = (array: number[]): number[] => {
  array.length--;
  return array;
};

// shift : xoá ở đầu
// O(n) Time Complexity, O(1) Space complexity
const shift = (array: number[]): number[] => {
  for (let i = 0; i < array.length; i++) {
    array[i] = array[i + 1];
  }
  array.length--;
  return array;
};

// unshift : thêm vào đầu
// O(n) Time Complexity, O(1) Space complexity
const unshift = (array: number[], number: number): number[] => {
  for (let i = array.length - 1; i >= 0; i--) {
    array[i + 1] = array[i];
  }
  array[0] = number;
  return array;
};

unshift([1, 2, 3, 4], 0);

//  [1,2,3,4]
// newArray []

// Bubble Sort O(n^2)