| | | 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.UglyNumber2; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class UglyNumber2DynamicProgramming : IUglyNumber2 |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="n"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public int NthUglyNumber(int n) |
| | 9 | 24 | | { |
| | 9 | 25 | | var uglyNumbers = new int[n]; |
| | | 26 | | |
| | 9 | 27 | | uglyNumbers[0] = 1; |
| | | 28 | | |
| | 9 | 29 | | var i2 = 0; |
| | 9 | 30 | | var i3 = 0; |
| | 9 | 31 | | var i5 = 0; |
| | | 32 | | |
| | 9 | 33 | | var nextMultipleOf2 = 2; |
| | 9 | 34 | | var nextMultipleOf3 = 3; |
| | 9 | 35 | | var nextMultipleOf5 = 5; |
| | | 36 | | |
| | 10362 | 37 | | for (var i = 1; i < n; i++) |
| | 5172 | 38 | | { |
| | 5172 | 39 | | var nextUgly = Math.Min(nextMultipleOf2, Math.Min(nextMultipleOf3, nextMultipleOf5)); |
| | | 40 | | |
| | 5172 | 41 | | uglyNumbers[i] = nextUgly; |
| | | 42 | | |
| | 5172 | 43 | | if (nextUgly == nextMultipleOf2) |
| | 4679 | 44 | | { |
| | 4679 | 45 | | i2++; |
| | | 46 | | |
| | 4679 | 47 | | nextMultipleOf2 = uglyNumbers[i2] * 2; |
| | 4679 | 48 | | } |
| | | 49 | | |
| | 5172 | 50 | | if (nextUgly == nextMultipleOf3) |
| | 4400 | 51 | | { |
| | 4400 | 52 | | i3++; |
| | | 53 | | |
| | 4400 | 54 | | nextMultipleOf3 = uglyNumbers[i3] * 3; |
| | 4400 | 55 | | } |
| | | 56 | | |
| | 5172 | 57 | | if (nextUgly == nextMultipleOf5) |
| | 4072 | 58 | | { |
| | 4072 | 59 | | i5++; |
| | | 60 | | |
| | 4072 | 61 | | nextMultipleOf5 = uglyNumbers[i5] * 5; |
| | 4072 | 62 | | } |
| | 5172 | 63 | | } |
| | | 64 | | |
| | 9 | 65 | | return uglyNumbers[n - 1]; |
| | 9 | 66 | | } |
| | | 67 | | } |