| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2025 Eugene Eremeev (also known as Yevhenii Yeriemeieiv). |
| | | 3 | | // All Rights Reserved. |
| | | 4 | | // -------------------------------------------------------------------------------- |
| | | 5 | | // This software is the confidential and proprietary information of Eugene Eremeev |
| | | 6 | | // (also known as Yevhenii Yeriemeieiv) ("Confidential Information"). You shall not |
| | | 7 | | // disclose such Confidential Information and shall use it only in accordance with |
| | | 8 | | // the terms of the license agreement you entered into with Eugene Eremeev (also |
| | | 9 | | // known as Yevhenii Yeriemeieiv). |
| | | 10 | | // -------------------------------------------------------------------------------- |
| | | 11 | | |
| | | 12 | | namespace LeetCode.Algorithms.ImplementQueueUsingStacks; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class ImplementQueueUsingStacksAmortized : IImplementQueueUsingStacks |
| | | 16 | | { |
| | 9 | 17 | | private readonly Stack<int> _dequeueStack = new(); |
| | 9 | 18 | | private readonly Stack<int> _enqueueStack = new(); |
| | | 19 | | |
| | | 20 | | /// <summary> |
| | | 21 | | /// Time complexity - O(1) |
| | | 22 | | /// Space complexity - O(n) |
| | | 23 | | /// </summary> |
| | | 24 | | /// <param name="x"></param> |
| | | 25 | | public void Push(int x) |
| | 14 | 26 | | { |
| | 14 | 27 | | _enqueueStack.Push(x); |
| | 14 | 28 | | } |
| | | 29 | | |
| | | 30 | | /// <summary> |
| | | 31 | | /// Time complexity - Amortized O(1), worst case - O(n) |
| | | 32 | | /// Space complexity - O(1) |
| | | 33 | | /// </summary> |
| | | 34 | | /// <returns></returns> |
| | | 35 | | public int Pop() |
| | 8 | 36 | | { |
| | 8 | 37 | | if (_dequeueStack.Count != 0) |
| | 4 | 38 | | { |
| | 4 | 39 | | return _dequeueStack.Pop(); |
| | | 40 | | } |
| | | 41 | | |
| | 11 | 42 | | while (_enqueueStack.Count > 0) |
| | 7 | 43 | | { |
| | 7 | 44 | | _dequeueStack.Push(_enqueueStack.Pop()); |
| | 7 | 45 | | } |
| | | 46 | | |
| | 4 | 47 | | return _dequeueStack.Pop(); |
| | 7 | 48 | | } |
| | | 49 | | |
| | | 50 | | /// <summary> |
| | | 51 | | /// Time complexity - Amortized O(1), worst case - O(n) |
| | | 52 | | /// Space complexity - O(1) |
| | | 53 | | /// </summary> |
| | | 54 | | /// <returns></returns> |
| | | 55 | | public int Peek() |
| | 3 | 56 | | { |
| | 3 | 57 | | if (_dequeueStack.Count != 0) |
| | 0 | 58 | | { |
| | 0 | 59 | | return _dequeueStack.Peek(); |
| | | 60 | | } |
| | | 61 | | |
| | 9 | 62 | | while (_enqueueStack.Count > 0) |
| | 6 | 63 | | { |
| | 6 | 64 | | _dequeueStack.Push(_enqueueStack.Pop()); |
| | 6 | 65 | | } |
| | | 66 | | |
| | 3 | 67 | | return _dequeueStack.Peek(); |
| | 2 | 68 | | } |
| | | 69 | | |
| | | 70 | | /// <summary> |
| | | 71 | | /// Time complexity - O(1) |
| | | 72 | | /// Space complexity - O(1) |
| | | 73 | | /// </summary> |
| | | 74 | | /// <returns></returns> |
| | | 75 | | public bool Empty() |
| | 7 | 76 | | { |
| | 7 | 77 | | return _enqueueStack.Count == 0 && _dequeueStack.Count == 0; |
| | 7 | 78 | | } |
| | | 79 | | } |