Stack & Queue

LIFO & FIFO structures, monotonic stacks & sliding windows

17 Problems

⌘K

Problem

Difficulty

Actions

01.

Implement Stack Using Arrays

Easy

02.

Implement Queue Using Arrays

Easy

03.

Implement Stack using Queue (using single queue)

Easy

04.

Implement Queue using Stack (0(1) amortized method)

Easy

05.

Check for balanced parentheses

Easy

06.

Next Greater Element

Medium

07.

Sort a Stack

Medium

08.

Next Smaller Element

Medium

09.

LRU cache

Medium

10.

LFU Cache

Hard

11.

Largest rectangle in a histogram

Hard

12.

Sliding Window maximum

Hard

13.

Implement Min Stack

Medium

14.

Rotten Orange (Using BFS)

Medium

15.

Stock Span Problem

Medium

16.

Find the maximum of minimums of every window size

Hard

17.

The Celebrity Problem

Medium