OrderedSet

tags: Sliding Window,OrderedSet Use HashSet to attempt to meet the requirements in the window class Solution { public: bool containsNearbyAlmostDuplicate(vector<int>& nums, int k, int t) { auto left = 0; auto K = 0; set<long> hset; // set in cpp is an sorted set for (auto right = 0; right < nums.size(); right++) { K = right - left; if (K > k) { hset.erase(nums[left]); left++; } hset.insert(nums[right]); // some numbers are the same. if (hset.size() < (right - left + 1)) { return true; } // abs less than or equal t auto prev = hset.begin(); for (auto iter = hset.begin(); iter != hset.end(); iter++) { if (iter != prev && abs(*prev - *iter) <= t) { return true; } prev = iter; } } return false; } }; // 1. find previous value that meet the requirement, which is abs(nums[i] - nums[j]) <= t // 2. See if also meet the requirement, which is abs(i - j) <= k, otherwise slide left // // Use a fixed window, which size is ~k~. And maintain a set of numbers in the window. // To check if there numbers meet the requirement. It’s too slow and got “Time Limit Exceeded”: https://leetcode.com/submissions/detail/658425251/testcase/. In this case the t is 0, so we can avoid the embed for loop with a if condition: ...