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HSK 4 | verb | to reflect a situation or to report a problem to a higher authority

HSK 1 | verb, noun | to answer, to reply, an answer

HSK 4 | adjective | friendly, amicable

HSK 5 | n | the form or style of a written work; literary genre

HSK 5 | noun | sovereignty; sovereign rights

HSK 5 | noun | newly reported events or information; news media

HSK 2 | adjective/noun | two readings: chā (difference/gap) and chà (substandard/lacking)

七 (shichi/nana-tsu): seven. JLPT N5 kanji.

時 (time, hour): 10 strokes, JLPT N5. On: ジ. Kun: とき.

HSK 4 | noun | a set of steps or instructions; a computer program

HSK 1 | noun | person, people, human being

HSK 3 | noun | a piece of news or information about recent events

HSK 5 | adjective | pushed to the margins; excluded from mainstream society

We are given a rooted tree with n nodes, each node assigned a positive integer value. Node 1 is the root. Queries ask either to find the deepest ancestor of a node v whose value shares a non-trivial greatest common divisor with v, or to update the value of a node.

HSK 3 | verb | to stay, to remain; to leave behind, to keep; to leave a message

HSK 5 | noun | contract, written agreement

HSK 2 | conjunction | then, after that (sequence connector)

HSK 3 | noun | grades, scores, results; the achievement produced by effort

HSK 5 | verb | to make something more profound or thorough

Master the nuances of formal Japanese conjunctions used to express basis, compliance, and alignment in professional and academic contexts.

Advanced theory and practice of translation into and from Esperanto — literary, technical, and cultural dimensions, with the translator's full toolkit.

HSK 2 | noun | question on a test, problem, topic

HSK 3 | adjective | complex, complicated, involving many parts or factors

HSK 3 | noun | doctor, physician — spoken/Northern Chinese term; compare 医生

HSK 3 | noun | the image or impression someone or something projects

HSK 2 | verb | to feel anxious or worried about someone or something

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

Conjugate Latin verbs in the present tense across all four conjugations plus the irregular verb esse.

HSK 2 | noun | physical body, health condition

HSK 4 | noun | a recurring sequence of events or a defined time span

一 (ichi/itsu/hito-tsu): one. JLPT N5 kanji.

HSK 4 | verb | to nurture and develop a skill, person, or quality

We are given an array a[1..n]. For every position i, define the value L[i] = number of occurrences of a[i] in the prefix [1..i]. For every position j, define R[j] = number of occurrences of a[j] in the suffix [j..n].

HSK 5 | noun | arrangement and organization of components within a whole

HSK 1 | noun | a point in time or a period; used in the pattern 的时候 (when)

HSK 5 | verb / noun | to analyze; analysis

HSK 2 | noun | a sovereign state or nation

HSK 1 | verb | movement toward the speaker's location

We have an $n times n$ bingo board. Every cell contains a distinct number chosen from $1$ to $m$, and every valid board is equally likely. After the board is generated, exactly $k$ distinct numbers are called. Every set of $k$ numbers is equally likely.

HSK 4 | verb | to face; to confront; to deal with

HSK 4 | noun | a strategy, tactic, or planned approach to achieving a goal

HSK 5 | noun/verb | hypothesis; assumption; to suppose; to assume

HSK 3 | noun | passport — official travel document

HSK 4 | adjective / verb | stable and steady; to make something stable

Learn 〜だけあって and 〜だけに to express outcomes that match or are expected given a particular quality or background.

HSK 4 | verb | to be in (a state, position, or situation)

HSK 3 | noun/adjective | customs and practices passed down through generations

HSK 1 | noun | telephone, phone call

HSK 5 | noun | regular, predictable pattern or law governing phenomena

HSK 4 | adverb | mostly true or largely complete

HSK 2 | adjective/adverb | clear, distinct, to understand clearly

HSK 5 | verb / noun | to call into question; to express doubt

HSK 3 | noun | sugar; candy, sweets

HSK 4 | adjective | easy to see or notice; clearly apparent

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

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

Essential Japanese vocabulary for computers, internet, devices, apps, digital life. N1 level reference with readings, romaji, and examples.

We are given an array of integers, a[1…n], and a recursive function f(i, j) defined on it. The function essentially accumulates sums along specific paths: the base case is simply f(1, j) = a[j], and for later rows, each f(i, j) is the sum of a[j] plus the minimum of f(i-1…

HSK 1 | number | the digit two; used in isolation, ordinals, and compound numbers

Learn to recognize and translate result (consecutive) clauses and indirect questions in classical Latin.

Command Esperanto's -ig- and -iĝ- suffixes to express causation and inchoative change, and understand how transitivity determines accusative use.

We are given a tree with n vertices, where some vertices are black and others are white. The tree is rooted implicitly by the way the edges are described: each node i for i 0 has a parent p[i-1].

HSK 1 | noun | hospital, medical facility

Engage with the major authors, works, and critical debates that constitute the Esperanto literary tradition from Zamenhof to the present day.

Learn how to use 〜をはじめ (wo hajime) to express 'starting with' or 'including' when listing a representative example of a broader group. Includes structure, nuance, examples, and comparisons.

HSK 4 | noun | a real-time audio and video call over the internet

HSK 3 | noun | library, a place to read and borrow books

HSK 3 | adverb | anyway, regardless, in any case — concedes a point but asserts another

HSK 4 | adjective/noun | something that is hard to do or a challenging situation

HSK 3 | noun | manufactured goods or output of a process

HSK 5 | verb/noun | to guide and direct an organisation or group; a leader or the act of leadership

HSK 4 | noun / verb | plan; to plan; to intend

HSK 3 | preposition | in accordance with, following a rule, method, or standard

The task asks us to find all positive integers less than one billion that satisfy the equation $$x = b cdot s(x) cdot a + c$$ where $a$, $b$, and $c$ are given constants, and $s(x)$ is the sum of the digits of $x$.

HSK 5 | noun/verb | the process of making important decisions, especially in policy or management

Learn four suffixes that create place words, professional titles, feminine forms, and person-descriptors from any root.

HSK 4 | verb / noun | to doubt; to suspect; doubt

Learn vocabulary for medical situations and healthy habits, and master the grammar patterns 应该 and 建议 for giving and receiving health advice.

Learn colors, basic appearance adjectives, and how to modify nouns with 的 and intensify descriptions with 很.

Understand and produce pivotal (兼语) sentences with 让, 叫, 请, 使, and related verbs at B1 level.

HSK 5 | verb | to show clearly; to express or demonstrate

N1 grammar pattern 〜といえども: formal concessive expressing 'although/even if/even though X, nevertheless Y.' Used in formal speeches, legal texts, academic writing.

HSK 5 | noun | a person who uses a product, service, or system

Mastering formal written and spoken Esperanto for business correspondence, academic writing, conference presentations, and professional contexts.

HSK 6 | n | the organized, regulated state of affairs in society, an institution, or nature

男 (man, male): 7 strokes, JLPT N5. On: ダン、ナン. Kun: おとこ.

HSK 5 | adjective/adverb | covering all aspects, thorough and complete

Learn 〜をもとに and 〜をもとにして to express using something as raw material, inspiration, or source for creating or analyzing something new.

HSK 4 | noun | a group of people working together toward a shared goal

HSK 3 | noun | fortune; chance; whether things go well or badly

外 (outside): 5 strokes, JLPT N5. On: ガイ、ゲ. Kun: そと、はず-れる.

HSK 5 | noun/verb | advancement or improvement in ability, knowledge, or society

Master the most frequently tested N1 proverbs (諺) and idiomatic set phrases (慣用句), understand their cultural and linguistic origins, and use them appropriately across formal and casual registers.

見 (ken/mi-ru): see. JLPT N5 kanji.

万 (ten thousand): 3 strokes, JLPT N5. On: マン、バン. Kun: よろず.

HSK 6 | verb | to subject to critical examination; to criticize fundamentally

HSK 3 | noun | a person's name or the name of something

HSK 5 | verb / noun | to identify a disease or problem; the diagnosis

下 (ka/ge/shita): below. JLPT N5 kanji.

自然 (しぜん / shizen): nature. N4 level Japanese vocabulary.