brain

HSK 2 | adverb | again (future repetition), then, one more time

We have an array of integers, each between 1 and n, and we need to support two types of operations efficiently. The first operation rotates a segment of the array one step to the right. The second operation counts how many times a particular value occurs in a segment.

We are asked to implement a simple Caesar cipher. The input gives us a key k, an integer between 0 and 25, which represents how many positions each letter in the message should be shifted forward in the alphabet.

N1 grammar: 〜いかんでは and 〜いかんによっては expressing 'depending on the nature/circumstances of X, Y may occur.' Formal register, often in legal or policy contexts.

We are given a line of ants, each with an integer strength. Mole wants to observe fights among ants in specified contiguous segments of the line. For a given segment from position l to r, every ant fights every other ant within that segment.

HSK 1 | noun | water

HSK 3 | verb | to be acquainted with someone; to recognize or identify

We are given a game with several players, each controlling an army composed of different types of soldiers. Each army is represented as a non-negative integer where the binary representation encodes the presence of soldier types: a bit set to 1 means the army includes that type.

HSK 4 | verb/adjective | to negate, to deny; negative

HSK 2 | verb + result complement | indicates buying resulted in actually obtaining the item

HSK 4 | verb / adjective | fulfilling a need or feeling content

HSK 1 | adjective | cheap, inexpensive, affordable

HSK 1 | particle | turns a statement into a yes/no question

HSK 4 | noun | colleague, coworker

HSK 1 | noun | dog

We are given a single integer n, where n ≥ 12. The task is to find any two composite numbers whose sum is exactly n. A composite number is an integer greater than 1 that has at least one divisor other than 1 and itself.

HSK 5 | noun | the foundational base upon which something is built

HSK 5 | noun | foreign exchange, foreign currency

HSK 3 | adverb | continuously, all along, straight — describes uninterrupted action or direction

それから (それから / sorekara): and then, after that. N4 level Japanese vocabulary.

HSK 5 | verb/adjective/noun | bringing together into a single coherent whole

Learn 〜得る (can possibly, is conceivable) and 〜得ない (cannot possibly, is inconceivable) — N3 patterns for logical possibility and impossibility.

HSK 5 | verb / adjective | to suppress, to repress; stifling, oppressive

We are given a line of floors from 1 to n. We start on floor a and we will make exactly k moves. Each move picks a new floor y different from the current floor x, but with a restriction: we are not allowed to move “too far” in absolute distance compared to a forbidden floor…

HSK 2 | verb phrase | to make or place a telephone call

HSK 5 | verb | to publish an article; to deliver a speech or statement

HSK 5 | noun/verb | practical application of theory; to apply knowledge in real action

HSK 4 | noun | the ability to accomplish something with minimal waste

HSK 4 | noun / conjunction | the final outcome of a process, or a connective meaning consequently

HSK 4 | noun | programs and operating information used by a computer

HSK 4 | noun | a person who manages or administers an organization or team

子 (child): 3 strokes, JLPT N5. On: シ、ス. Kun: こ.

HSK 5 | verb/noun | development of diversity and variety in forms or approaches

Master multi-affix stacking, productive derivation chains, and the principles behind Esperanto neologism formation at B2 level.

Learn to decode unfamiliar Esperanto words using word-building knowledge, cognates, and context clues, and build a reading practice with graded and authentic texts.

HSK 2 | verb | to go to work, to start a work shift

HSK 4 | adjective | not complex or difficult; lacking unnecessary detail

HSK 1 | noun | mobile phone, smartphone

四 (four): 5 strokes, JLPT N5. On: シ. Kun: よ、よ-つ、よっ-つ、よん.

Learn five productive Esperanto prefixes that multiply your vocabulary by expressing opposites, beginnings, repetition, dispersal, and errors.

The problem asks us to take a list of integers and, for each element, produce the sum of that element with the element immediately preceding it. The twist is that the first element of the output pairs with the last element of the array, creating a circular relationship.

HSK 4 | verb | to move downward in level or amount

HSK 3 | noun | ears, the organs of hearing

HSK 5 | noun / adjective | the activity of governance; relating to political affairs

HSK 5 | verb / noun | to research and develop (R&D)

HSK 3 | verb/noun | to personally feel or go through something

HSK 4 | verb/noun | to publicize, to promote; publicity, propaganda

HSK 5 | noun | a biological classification grouping organisms that can interbreed

食 (eat, food): 9 strokes, JLPT N5. On: ショク、ジキ. Kun: た-べる、く-う.

HSK 3 | grammar pattern | expresses whether an action can or cannot achieve its result

HSK 4 | n | a legally recognized member of a state

HSK 1 | adjective | hot (temperature or weather)

HSK 3 | adjective/noun | able to wait calmly without frustration

Using 成语 naturally: understanding origin, semantic evolution, and pragmatic deployment in sophisticated discourse.

HSK 3 | adjective | strict, rigorous, demanding — high standards with no exceptions

Navigate Chinese economic discourse with confidence, mastering the vocabulary of finance, macroeconomics, and business reporting.

Learn 〜たびに (every time, whenever) — the N3 pattern for expressing a consistent pattern of recurrence with emotional weight.

HSK 4 | noun | the power or skill to do something

山 (san/yama): mountain. JLPT N5 kanji.

HSK 1 | pronoun | first-person plural pronoun

We have all lattice points inside and on the boundary of an axis-aligned rectangle whose opposite corners are (0, 0) and (n, m). The task is to choose four distinct lattice points and connect them in the chosen order.

Complete N3 vocabulary reference: ~2,250 new words beyond N4, organized by semantic domain. Abstract nouns, workplace terms, academic vocabulary, emotional states, and more.

Complete katakana chart with all 46 base characters, variants, combination characters, long vowel mark, loanword spelling rules, and common vocabulary examples.

HSK 5 | verb / noun | to plan and create; a plan or design

HSK 4 | verb/noun | to strive against others for the same goal or resource

HSK 4 | verb / noun | to gradually accumulate or build up over time

Sindarin word-building with prefixes: directional, negative, intensifying, and stative prefixes with 40+ examples from attested names.

Sindarin conditional mood using aen and the subjunctive: expressing hypothetical situations, wishes, and uncertainty.

HSK 4 | adjective/verb | fully developed, either physically or mentally

Talk about your job, workplace, and colleagues in Chinese with natural professional vocabulary.

HSK 1 | noun | English language

HSK 5 | noun | public opinion, public discourse, media opinion

HSK 3 | verb | to raise, improve, or enhance a level or standard

目 (eye): 5 strokes, JLPT N5. On: モク、ボク. Kun: め.

Sindarin mixed mutation: the third mutation type triggered by definite prepositions — the complete change table, all triggering constructions, and worked examples.

HSK 5 | verb / noun | to owe debts; liabilities on a balance sheet

猫 (cat): 11 strokes, JLPT N5. On: ビョウ. Kun: ねこ.

HSK 5 | verb | to breed, to nurture, to cultivate (plants, organisms, or people)

HSK 4 | adjective/noun | relating to a specific field of expertise

Talk about what happened using the completion marker 了, negate past actions with 没有, and use 刚才 for recent events.

Master the two distinct uses of 〜次第: 'depending on' (conditional) and 'as soon as' (sequence), a critical N2 exam distinction.

HSK 8 vocabulary reference: advanced C2-level words in specialist academic disciplines, technology, and professional domains.

N1 grammar pattern 〜ならでは: expressing uniqueness or exclusivity — 'only possible with ~, uniquely characteristic of ~, something only ~ can offer.'

HSK 3 | noun | a feeling of curiosity or enjoyment toward something

HSK 3 | noun | the material or substance contained within something

HSK 6 | verb | to bring together disparate elements into a unified whole

JLPT N4 kanji 首 — readings, vocabulary, stroke order, mnemonic, and common confusion pairs.

HSK 4 | verb/noun | granting official permission or power to someone

〜かもしれない: JLPT N4 grammar pattern. Usage, structure, examples, and comparison with similar patterns.

HSK 1 | verb, adverb | please, to invite, to treat someone

HSK 5 | verb | to bring separate elements together into a unified, coherent whole

Mastering the full academic register for publication-standard Chinese scholarly writing.

HSK 3 | noun | a room or building used for work

HSK 3 | verb | to depart, set off, or start a journey

HSK 4 | adverb | indicating an estimate rather than an exact figure

HSK 3 | verb | to manage, to be in charge of; to bother with, to concern oneself with

HSK 2 | measure word | counts songs and poems as complete compositions

HSK 4 | adjective | going beyond the surface to reveal essential truth or insight

HSK 3 | verb | to make something smaller in amount or number

Sindarin past tense formation: strong past (vowel change + nasal infixion) for primary verbs and weak past (-ant suffix) for A-stem verbs, with all 6 persons.