https://algorithm.liangqin.ren/tags/table/Recent content in Table on Algorithm SolutionsHugo -- gohugo.ioThu, 24 Sep 2026 20:29:24 -0500https://algorithm.liangqin.ren/oa/6/Thu, 24 Sep 2026 20:29:24 -0500https://algorithm.liangqin.ren/oa/6/1. Description You are given an array of positive integers numbers. A pair of indices (i, j), where i < j, is valid if numbers[i] can be transformed into numbers[j] by swapping at most two digits in one of the numbers. No swap is also allowed. Return the number of valid pairs. 2. Solution n = numbers.size() Time complexity: O(n$^2$) Space complexity: O(n) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 int solution(const vector<int>& numbers) { unordered_map<string, vector<string>> buckets; for (int num : numbers) { string s = to_string(num); string key = s; sort(key.