| | | 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 | | using System.Text; |
| | | 13 | | |
| | | 14 | | namespace LeetCode.Algorithms.MultiplyStrings; |
| | | 15 | | |
| | | 16 | | /// <inheritdoc /> |
| | | 17 | | public class MultiplyStringsIterative : IMultiplyStrings |
| | | 18 | | { |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n * m) |
| | | 21 | | /// Space complexity - O(n + m) |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="num1"></param> |
| | | 24 | | /// <param name="num2"></param> |
| | | 25 | | /// <returns></returns> |
| | | 26 | | public string Multiply(string num1, string num2) |
| | 5 | 27 | | { |
| | 5 | 28 | | if (num1 == "0" || num2 == "0") |
| | 1 | 29 | | { |
| | 1 | 30 | | return "0"; |
| | | 31 | | } |
| | | 32 | | |
| | 4 | 33 | | var result = new int[num1.Length + num2.Length]; |
| | | 34 | | |
| | 28 | 35 | | for (var i = num1.Length - 1; i >= 0; i--) |
| | 10 | 36 | | { |
| | 94 | 37 | | for (var j = num2.Length - 1; j >= 0; j--) |
| | 37 | 38 | | { |
| | 37 | 39 | | var product = (int)char.GetNumericValue(num1[i]) * (int)char.GetNumericValue(num2[j]); |
| | 37 | 40 | | var p1 = i + j; |
| | 37 | 41 | | var p2 = i + j + 1; |
| | 37 | 42 | | var sum = product + result[p2]; |
| | | 43 | | |
| | 37 | 44 | | result[p1] += sum / 10; |
| | 37 | 45 | | result[p2] = sum % 10; |
| | 37 | 46 | | } |
| | 10 | 47 | | } |
| | | 48 | | |
| | 4 | 49 | | var resultStringBuilder = new StringBuilder(); |
| | | 50 | | |
| | 58 | 51 | | foreach (var num in result) |
| | 23 | 52 | | { |
| | 23 | 53 | | if (!(resultStringBuilder.Length == 0 && num == 0)) |
| | 21 | 54 | | { |
| | 21 | 55 | | resultStringBuilder.Append(num); |
| | 21 | 56 | | } |
| | 23 | 57 | | } |
| | | 58 | | |
| | 4 | 59 | | return resultStringBuilder.Length == 0 ? "0" : resultStringBuilder.ToString(); |
| | 5 | 60 | | } |
| | | 61 | | } |