#1381 - Design a Stack With Increment Operation

Problem Description

Design a stack that supports increment operations on its elements.

Implement the CustomStack class:

CustomStack(int maxSize) Initializes the object with maxSize which is the maximum number of elements in the stack.
void push(int x) Adds x to the top of the stack if the stack has not reached the maxSize.
int pop() Pops and returns the top of the stack or -1 if the stack is empty.
void inc(int k, int val) Increments the bottom k elements of the stack by val. If there are less than k elements in the stack, increment all the elements in the stack.

Solution

/**
 * @param {number} maxSize
 */
var CustomStack = function(maxSize) {
  this.elements = [];
  this.capacity = maxSize;
};

/**
 * @param {number} x
 * @return {void}
 */
CustomStack.prototype.push = function(x) {
  if (this.elements.length < this.capacity) {
    this.elements.push(x);
  }
};

/**
 * @return {number}
 */
CustomStack.prototype.pop = function() {
  return this.elements.length ? this.elements.pop() : -1;
};

/**
 * @param {number} k
 * @param {number} val
 * @return {void}
 */
CustomStack.prototype.increment = function(k, val) {
  const limit = Math.min(k, this.elements.length);
  for (let i = 0; i < limit; i++) {
    this.elements[i] += val;
  }
};