{ "data": { "question": { "questionId": "2821", "questionFrontendId": "2715", "boundTopicId": null, "title": "Timeout Cancellation", "titleSlug": "timeout-cancellation", "content": "

Given a function fn, an array of arguments args, and a timeout t in milliseconds, return a cancel function cancelFn.

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After a delay of t, fn should be called with args passed as parameters unless cancelFn was invoked before the delay of t milliseconds elapses, specifically at cancelT ms. In that case, fn should never be called.

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Example 1:

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\nInput: fn = (x) => x * 5, args = [2], t = 20, cancelT = 50\nOutput: [{"time": 20, "returned": 10}]\nExplanation: \nconst cancel = cancellable((x) => x * 5, [2], 20); // fn(2) called at t=20ms\nsetTimeout(cancel, 50);\n\nThe cancellation was scheduled to occur after a delay of cancelT (50ms), which happened after the execution of fn(2) at 20ms.\n
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Example 2:

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\nInput: fn = (x) => x**2, args = [2], t = 100, cancelT = 50 \nOutput: []\nExplanation: \nconst cancel = cancellable((x) => x**2, [2], 100); // fn(2) not called\nsetTimeout(cancel, 50);\n\nThe cancellation was scheduled to occur after a delay of cancelT (50ms), which happened before the execution of fn(2) at 100ms, resulting in fn(2) never being called.\n
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Example 3:

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\nInput: fn = (x1, x2) => x1 * x2, args = [2,4], t = 30, cancelT = 100\nOutput: [{"time": 30, "returned": 8}]\nExplanation:\nconst cancel = cancellable((x1, x2) => x1 * x2, [2,4], 30); // fn(2,4) called at t=30ms\nsetTimeout(cancel, 100);\n\nThe cancellation was scheduled to occur after a delay of cancelT (100ms), which happened after the execution of fn(2,4) at 30ms.\n
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Constraints:

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Node.js 16.13.2.

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Your code is run with --harmony flag, enabling new ES6 features.

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lodash.js library is included by default.

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For Priority Queue / Queue data structures, you may use 5.3.0 version of datastructures-js/priority-queue and 4.2.1 version of datastructures-js/queue.

\"], \"typescript\": [\"Typescript\", \"

TypeScript 5.1.6, Node.js 16.13.2.

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Your code is run with --harmony flag, enabling new ES2022 features.

\\r\\n\\r\\n

lodash.js library is included by default.

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