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LeetCode solutions

2821. Timeout Cancellation

My accepted JavaScript solution to LeetCode problem 2821, Timeout Cancellation, running in 72ms.

  • Difficulty: Easy
  • JavaScript
  • Runtime 72ms
  • Memory 53.2MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

JavaScript

Accepted on LeetCode — runtime 72ms, memory 53.2MB, accepted 2025-12-31.

javascript
/**
 * @param {Function} fn
 * @param {Array} args
 * @param {number} t
 * @return {Function}
 */
var cancellable = function(fn, args, t) {
    const timeoutId = setTimeout(() => fn(...args), t);
    return function cancelFn() {
        clearTimeout(timeoutId);
    };
};

/**
 *  const result = [];
 *
 *  const fn = (x) => x * 5;
 *  const args = [2], t = 20, cancelTimeMs = 50;
 *
 *  const start = performance.now();
 *
 *  const log = (...argsArr) => {
 *      const diff = Math.floor(performance.now() - start);
 *      result.push({"time": diff, "returned": argsArr[0]});
 *  }
 *       
 *  const cancel = cancellable((x) => { log(x * 5); }, args, t);
 *
 *  const maxT = Math.max(t, cancelTimeMs);
 *           
 *  setTimeout(cancel, cancelTimeMs);
 *
 *  setTimeout(() => {
 *      console.log(result); // [{"time":20,"returned":10}]
 *  }, maxT + 15)
 */

Source