leetcode\ImplementQueueUsingStacks2

Complexity

Total Complexity

8

Size/Duplication

Total Lines	35
Duplicated Lines	0 %

Importance

Changes	2
Bugs	0	Features	0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	push()	0	3	1
A	peek()	0	13	4
A	empty()	0	3	2
A	pop()	0	5	1

<?php

declare(strict_types=1);

namespace leetcode;

class ImplementQueueUsingStacks2
{
    private array $cache;
    private array $stack;

    public function push(int $value): void
    {
        $this->cache[] = $value;
    }

    public function pop(): ?int
    {
        $this->peek();

        return array_shift($this->stack);
    }

    public function peek(): ?int
    {
        if (empty($this->stack)) {
            while (!empty($this->cache)) {
                $this->stack[] = array_shift($this->cache);
            }
        }

        if (empty($this->stack)) {
            return null;
        }

        return current($this->stack);
    }

    public function empty(): bool
    {
        return empty($this->stack) && empty($this->cache);
    }
}