https://h30306.github.io/blog/tags/heap/Recent content in Heap onHugo -- gohugo.ioenhwork0511@gmail.com (Wei Yi Chung)hwork0511@gmail.com (Wei Yi Chung)© 2026 Wei Yi ChungTue, 20 Oct 2026 00:00:00 +0000https://h30306.github.io/blog/algorithm/heap/Tue, 20 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/algorithm/heap/heapq basics, Top-K, lazy deletion, two heaps, k-way merge, sweep line, and Dijkstrahttps://h30306.github.io/blog/leetcode/leetcode-23/Tue, 20 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-23/LeetCode 23 note: a heap that holds only k heads, and divide-and-conquer pairwise merginghttps://h30306.github.io/blog/leetcode/leetcode-253/Thu, 15 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-253/LeetCode 253 note: a heap of end times for running meetings; half-open intervals need &lt;=https://h30306.github.io/blog/leetcode/leetcode-716/Mon, 14 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-716/LeetCode 716 note: store unique ids on both the stack and the heap, record deletions by id, and discard deleted entries lazily; tracking values cannot tell duplicates aparthttps://h30306.github.io/blog/leetcode/leetcode-2973/Sat, 12 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-2973/LeetCode 2973 note: the max product of three is either the three largest or the two smallest times the largest, so each subtree returns only its 2 smallest and 3 largest values, merged in post-orderhttps://h30306.github.io/blog/leetcode/leetcode-4046/Fri, 11 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-4046/LeetCode 4046 note: Dijkstra with the last direction and the turns used in the state; for the same cell and direction, an earlier pop is cheaper, and if it also used fewer turns it dominates later stateshttps://h30306.github.io/blog/leetcode/leetcode-1425/Thu, 10 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1425/LeetCode 1425 note: dp[i] = nums[i] + max(0, max of the previous k dp values); that max is a sliding window maximum, available in O(1) from a monotonic dequehttps://h30306.github.io/blog/leetcode/leetcode-1354/Mon, 07 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1354/LeetCode 1354 note: work backwards, since the maximum was set last; jump with a modulo when the gap is largehttps://h30306.github.io/blog/leetcode/leetcode-499/Sun, 06 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-499/LeetCode 499 note: Dijkstra prioritized by (distance, path string), and the ball stops when it rolls over the holehttps://h30306.github.io/blog/leetcode/leetcode-2163/Sat, 05 Sep 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-2163/LeetCode 2163 note: try every boundary k between the two parts; the left takes the n smallest of nums[:k] (a max-heap) and the right the n largest of nums[k:] (a min-heap), one prefix and one suffix passhttps://h30306.github.io/blog/leetcode/leetcode-2102/Sat, 01 Aug 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-2102/LeetCode 2102 note: two heaps for &ldquo;top k&rdquo; and &ldquo;the rest&rdquo;, with a custom <strong>lt</strong> for reversed string orderhttps://h30306.github.io/blog/leetcode/leetcode-1878/Tue, 23 Jun 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1878/LeetCode 1878 note: enumerate every top vertex and size, walk the four edges, and keep the three largest distinct sumshttps://h30306.github.io/blog/leetcode/leetcode-759/Sun, 03 May 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-759/LeetCode 759 note: k-way merge all work intervals by start; any gap after the latest end so far is common free timehttps://h30306.github.io/blog/leetcode/leetcode-1514/Fri, 17 Apr 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1514/LeetCode 1514 note: multiplying probabilities only shrinks them, so Dijkstra applies; prune with &lt;=https://h30306.github.io/blog/leetcode/leetcode-3885/Sun, 29 Mar 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-3885/LeetCode 3885 note: a dict of current priorities plus a max-heap with lazy deletion, validated on pophttps://h30306.github.io/blog/leetcode/leetcode-2054/Wed, 04 Feb 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-2054/LeetCode 2054 note: with at most two events, pair each event with the most valuable event that ends before it starts; sort by end time and use a prefix max with binary searchhttps://h30306.github.io/blog/leetcode/leetcode-3815/Sun, 18 Jan 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-3815/LeetCode 3815 note: one max-heap per item, push a new entry on every bid change, and drop stale entries on queryhttps://h30306.github.io/blog/leetcode/leetcode-632/Sun, 18 Jan 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-632/LeetCode 632 note: a heap of each list&rsquo;s current element plus the running maximum; always advance the smallesthttps://h30306.github.io/blog/leetcode/leetcode-1696/Sun, 10 Aug 2025 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1696/LeetCode 1696 note: dp[i] = nums[i] + max of the previous k dp values, with that max kept by a monotonic deque in O(n)https://h30306.github.io/blog/leetcode/leetcode-2402/Thu, 17 Jul 2025 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-2402/LeetCode 2402 note: one heap for free rooms and one for busy rooms; a delayed meeting keeps its original lengthhttps://h30306.github.io/blog/leetcode/leetcode-1353/Mon, 07 Jul 2025 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1353/LeetCode 1353 note: each day, attend the event that ends earliest, using a min-heap of end dayshttps://h30306.github.io/blog/leetcode/leetcode-3607/Sun, 06 Jul 2025 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-3607/LeetCode 3607 note: Union-Find groups, one min-heap per group, and lazy deletion for offline stations