https://jeanphilogong.github.io/jeanblog/tags/stack/Recent content in Stack on Jeanphilo BlogHugo -- 0.168.0en-usFri, 21 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/155-min-stack/Fri, 21 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/155-min-stack/Start from restoring the previous minimum after pop, build a correct scan baseline, and derive an O(1) Min Stack with synchronized prefix minima.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/20-valid-parentheses/Fri, 21 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/20-valid-parentheses/Start from the counterexample ([)], separate equal bracket counts from correct types and closing order, and derive an O(n) stack solution.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/394-decode-string/Fri, 21 Aug 2026 00:00:00 +0000https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/394-decode-string/Start from the context lost by nested encoding, build a correct recursive parser, and make its saved frames explicit with a stack.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/84-largest-rectangle-in-histogram/Mon, 20 Jul 2026 00:00:00 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/84-largest-rectangle-in-histogram/Start from the shortest bar in a contiguous interval, build an interval baseline, then derive a linear monotonic-stack solution that settles maximal widths.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/739-daily-temperatures/Wed, 15 Jul 2026 00:00:00 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/739-daily-temperatures/Start from an O(n^2) right-scan baseline, derive a monotonic stack of unresolved indices, and solve LeetCode 739 in O(n) time.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/binary-tree/230-kth-smallest-element-in-a-bst/Mon, 20 Apr 2026 10:01:46 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/binary-tree/230-kth-smallest-element-in-a-bst/A practical guide to LeetCode 230 covering why inorder traversal of a BST is sorted, how to count visits with an explicit stack, and how to stop immediately at the k-th node.https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/binary-tree/94-binary-tree-inorder-traversal/Fri, 06 Mar 2026 17:58:21 +0800https://jeanphilogong.github.io/jeanblog/alg/leetcode/hot100/binary-tree/94-binary-tree-inorder-traversal/A practical guide to LeetCode 94 covering left-root-right traversal, recursion, explicit stacks, engineering mappings, and runnable multi-language implementations.