| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2026 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.IntersectionOfMultipleArrays; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class IntersectionOfMultipleArraysCounting : IIntersectionOfMultipleArrays |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n * m), where n is the number of arrays in nums and m is the length of arrays in nums |
| | | 19 | | /// Space complexity - O(1) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="nums"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public IList<int> Intersection(int[][] nums) |
| | 2 | 24 | | { |
| | 2 | 25 | | Span<int> numsFrequencies = stackalloc int[1001]; |
| | | 26 | | |
| | 14 | 27 | | for (var i = 0; i < nums.Length; i++) |
| | 5 | 28 | | { |
| | 5 | 29 | | var row = nums[i]; |
| | | 30 | | |
| | 48 | 31 | | for (var j = 0; j < row.Length; j++) |
| | 19 | 32 | | { |
| | 19 | 33 | | var cell = row[j]; |
| | | 34 | | |
| | 19 | 35 | | numsFrequencies[cell]++; |
| | 19 | 36 | | } |
| | 5 | 37 | | } |
| | | 38 | | |
| | 2 | 39 | | var result = new List<int>(); |
| | | 40 | | |
| | 4008 | 41 | | for (var i = 0; i < numsFrequencies.Length; i++) |
| | 2002 | 42 | | { |
| | 2002 | 43 | | var numsFrequency = numsFrequencies[i]; |
| | | 44 | | |
| | 2002 | 45 | | if (numsFrequency == nums.Length) |
| | 2 | 46 | | { |
| | 2 | 47 | | result.Add(i); |
| | 2 | 48 | | } |
| | 2002 | 49 | | } |
| | | 50 | | |
| | 2 | 51 | | return result; |
| | 2 | 52 | | } |
| | | 53 | | } |