Generated by Codex with GPT-5
MEDIUMArray, Divide and Conquer, Sorting, Heap (Priority Queue), QuickselectThis problem asks for the value that would appear in position k if the array
were sorted in descending order.
Generated by Codex with GPT-5
MEDIUMArray, Two Pointers, Greedy, Sorting, Heap (Priority Queue)Each interval represents one meeting with a start time and an end time.
The question is not really about building a calendar or labeling rooms. It is asking:
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MEDIUMArray, Hash Table, Bucket Sort, HeapThe input is an array of integers and a number k.
The task is not to sort the array itself. It is to:
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MEDIUMArray, Binary SearchKoko has several piles of bananas and exactly h hours before the guards return. In one hour, she chooses one pile and eats up to k bananas from that pile. If the pile has fewer than k, she finishes it and the rest of that hour is wasted.
Generated by Codex with GPT-5
HARDArray, String, Backtracking, Trie, MatrixThe input gives a letter grid and a list of candidate words. A word is valid if it can be traced through horizontally or vertically adjacent cells without reusing the same cell inside that one word.
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HARDArray, Sorting, Heap (Priority Queue), Simulation17.6This is not the classic “how many meeting rooms are needed?” question.
The number of rooms is fixed up front, and every meeting has to be assigned under three rules:
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HARDArray, Dynamic ProgrammingThis problem looks like a simulation question, but the hard part is not the simulation itself. The hard part is that every burst changes the future.
When balloon i is burst, the coins earned are:
Generated by Codex with GPT-5
HARDArray, Breadth-First Search, Heap (Priority Queue), Matrix17.6This is the 2D version of Trapping Rain Water.
Instead of one row of bars, there is a full grid of elevations. After rain falls, water can sit on low cells, but only if every path from that cell to the outer border is blocked by walls that are high enough.
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MEDIUMHash Table, Linked ListEach node in the list has two outgoing pointers:
next, which gives the usual linked-list orderrandom, which can point to any node in the list or to NoneThe task is to build a deep copy, not just another pointer to the same nodes.
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MEDIUMMath, Bit ManipulationTwo integers are given: dividend and divisor.
The task is to return the integer quotient of dividend / divisor, but with three constraints that make the problem interesting: