Generated by Codex with GPT-5
HARDString, Dynamic Programming, GreedyThe pattern contains two special characters:
? matches exactly one character* matches any sequence of characters, including the empty sequenceThe match must cover the entire string. That is the part that makes the problem interesting.
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HARDMath, RecursionThe numbers 1 through n can form n! different permutations in lexicographic order.
The problem asks for the kth permutation in that ordering without generating all the earlier ones first.
Generated by Codex with GPT-5
HARDArray, String, SimulationThe input is a list of words and a fixed line width. The task is to break the words into lines and return the exact text layout that a formatter would produce.
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MEDIUMLinked List, Recursion, Iteration, Pointer ManipulationThe input is the head of a singly linked list. Every adjacent pair of nodes must be swapped:
1 -> 2 -> 3 -> 4 becomes 2 -> 1 -> 4 -> 31 -> 2 -> 3 becomes 2 -> 1 -> 3The important constraint is that node values cannot be copied around. The solution has to rewire the list itself.
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MEDIUMArray, Two Pointers, Binary SearchThe input has length n + 1, but every value is guaranteed to be in the range 1 through n.
That guarantee means one value must appear more than once. So the duplicate is not the hard part. The hard part is satisfying the interview constraints at the same time:
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MEDIUMGraph, DFS, BFS, Union-FindEach equation like a / b = 2.0 gives a multiplicative relationship between two variables.
The query x / y asks:
can the known equations connect x to y, and if they can, what ratio do those equations imply?
Generated by Codex with GPT-5
MEDIUMMath, RecursionThe task is to compute x^n, but the real constraint is not the arithmetic itself. It is that n can be very large, including negative values, so a straightforward loop that multiplies x by itself |n| times is too slow.
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This article argues that the Voyager spacecraft have done something more interesting than simply becoming the first human-made objects to enter interstellar space. They have exposed how incomplete scientists’ picture of the sun’s outer domain really was. For decades the heliosphere, the vast bubble carved out by the solar wind and the sun’s magnetic field, was easy to draw in a diagram and hard to observe directly. The Voyagers changed that. By surviving long after their original grand tour of the outer planets, they turned into the only functioning probes to sample the boundary between the sun’s influence and the wider galaxy from the inside out.
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Techmeme surfaced this April 17, 2026 story, and the original article is TechCrunch’s Anthropic launches Claude Design, a new product for creating quick visuals.
Anthropic says Claude Design is an experimental product for turning prompts into presentation slides, one-pagers, prototypes, and other lightweight visual artifacts. The target user is not a full-time designer. It is the founder, product manager, operator, or teammate who has an idea and needs something more concrete than a wall of text, but faster than opening a full design tool from scratch.
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This summary covers The Economist’s March 28th, 2026 Europe article listed in the contents as The internet in Russia and headlined on the page as Spring offensive.
The article argues that Russia’s leadership is trying to turn internet access into another instrument of wartime control. Security services have begun blocking mobile internet and moving against Telegram not because Russia feels secure, but because the regime feels exposed. In trying to seal the country off from outside influence, the Kremlin is disrupting daily life in its biggest cities and alarming parts of its own elite.
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