| | | 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.DifferentWaysToAddParentheses; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class DifferentWaysToAddParenthesesDictionary : IDifferentWaysToAddParentheses |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n * 2^n) |
| | | 19 | | /// Space complexity - O(4^n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="expression"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public IList<int> DiffWaysToCompute(string expression) |
| | 5 | 24 | | { |
| | 5 | 25 | | return DiffWaysToCompute(expression, new Dictionary<string, IList<int>>()); |
| | 5 | 26 | | } |
| | | 27 | | |
| | | 28 | | private static IList<int> DiffWaysToCompute(string expression, Dictionary<string, IList<int>> expressionsDictionary) |
| | 143 | 29 | | { |
| | 143 | 30 | | if (expressionsDictionary.TryGetValue(expression, out var value)) |
| | 91 | 31 | | { |
| | 91 | 32 | | return value; |
| | | 33 | | } |
| | | 34 | | |
| | 52 | 35 | | var results = new List<int>(); |
| | | 36 | | |
| | 52 | 37 | | if (int.TryParse(expression, out var number)) |
| | 18 | 38 | | { |
| | 18 | 39 | | results.Add(number); |
| | | 40 | | |
| | 18 | 41 | | expressionsDictionary[expression] = results; |
| | | 42 | | |
| | 18 | 43 | | return results; |
| | | 44 | | } |
| | | 45 | | |
| | 472 | 46 | | for (var i = 0; i < expression.Length; i++) |
| | 202 | 47 | | { |
| | 202 | 48 | | if (char.IsDigit(expression[i])) |
| | 133 | 49 | | { |
| | 133 | 50 | | continue; |
| | | 51 | | } |
| | | 52 | | |
| | 69 | 53 | | var leftResults = DiffWaysToCompute(expression[..i], expressionsDictionary); |
| | 69 | 54 | | var rightResults = DiffWaysToCompute(expression[(i + 1)..], expressionsDictionary); |
| | | 55 | | |
| | 423 | 56 | | foreach (var leftResult in leftResults) |
| | 108 | 57 | | { |
| | 256 | 58 | | results.AddRange(rightResults.Select(rightResult => expression[i] switch |
| | 256 | 59 | | { |
| | 54 | 60 | | '+' => leftResult + rightResult, |
| | 78 | 61 | | '-' => leftResult - rightResult, |
| | 16 | 62 | | '*' => leftResult * rightResult, |
| | 0 | 63 | | _ => 0 |
| | 256 | 64 | | })); |
| | 108 | 65 | | } |
| | 69 | 66 | | } |
| | | 67 | | |
| | 34 | 68 | | expressionsDictionary.Add(expression, results); |
| | | 69 | | |
| | 34 | 70 | | return results; |
| | 143 | 71 | | } |
| | | 72 | | } |