| | | 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.AddStrings; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class AddStringsLinear : IAddStrings |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(max(n, m)) |
| | | 19 | | /// Space complexity - O(max(n, m)) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="num1"></param> |
| | | 22 | | /// <param name="num2"></param> |
| | | 23 | | /// <returns></returns> |
| | | 24 | | public string AddStrings(string num1, string num2) |
| | 4 | 25 | | { |
| | 4 | 26 | | var result = new char[Math.Max(num1.Length, num2.Length) + 1]; |
| | | 27 | | |
| | 4 | 28 | | var num1Index = num1.Length - 1; |
| | 4 | 29 | | var num2Index = num2.Length - 1; |
| | 4 | 30 | | var resultIndex = result.Length - 1; |
| | | 31 | | |
| | 4 | 32 | | var carry = 0; |
| | | 33 | | |
| | 30 | 34 | | while (num1Index >= 0 || num2Index >= 0) |
| | 26 | 35 | | { |
| | 26 | 36 | | var sum = carry; |
| | | 37 | | |
| | 26 | 38 | | if (num1Index >= 0) |
| | 25 | 39 | | { |
| | 25 | 40 | | sum += (int)char.GetNumericValue(num1[num1Index]); |
| | 25 | 41 | | num1Index--; |
| | 25 | 42 | | } |
| | | 43 | | |
| | 26 | 44 | | if (num2Index >= 0) |
| | 25 | 45 | | { |
| | 25 | 46 | | sum += (int)char.GetNumericValue(num2[num2Index]); |
| | 25 | 47 | | num2Index--; |
| | 25 | 48 | | } |
| | | 49 | | |
| | 26 | 50 | | carry = sum / 10; |
| | 26 | 51 | | result[resultIndex--] = (char)((sum % 10) + '0'); |
| | 26 | 52 | | } |
| | | 53 | | |
| | 4 | 54 | | if (carry <= 0) |
| | 3 | 55 | | { |
| | 3 | 56 | | return new string(result, resultIndex + 1, result.Length - resultIndex - 1); |
| | | 57 | | } |
| | | 58 | | |
| | 1 | 59 | | result[resultIndex] = (char)(carry + '0'); |
| | | 60 | | |
| | 1 | 61 | | return new string(result).TrimStart('0'); |
| | 4 | 62 | | } |
| | | 63 | | } |