Leetcode #2805: Custom Interval
In this guide, we solve Leetcode #2805 Custom Interval in Python and focus on the core idea that makes the solution efficient.
You will see the intuition, the step-by-step method, and a clean Python implementation you can use in interviews.
Problem Statement
Function customInterval Given a function fn, a number delay and a number period, return a number id. customInterval is a function that should execute the provided function fn at intervals based on a linear pattern defined by the formula delay + period * count.
Quick Facts
- Difficulty: Medium
- Premium: Yes
- Tags: JavaScript
Intuition
The constraints allow a direct scan that keeps only the essential state.
By translating the requirements into a clean loop, the logic stays easy to reason about.
Approach
Iterate through the data once, updating the state needed to compute the answer.
Return the final state after the traversal is complete.
Steps:
- Parse the input.
- Iterate and update state.
- Return the computed answer.
Example
Input: delay = 50, period = 20, cancelTime = 225
Output: [50,120,210]
Explanation:
const t = performance.now()
const result = []
const fn = () => {
result.push(Math.floor(performance.now() - t))
}
const id = customInterval(fn, delay, period)
setTimeout(() => {
customClearInterval(id)
}, 225)
50 + 20 * 0 = 50 // 50ms - 1st function call
50 + 20 * 1 = 70 // 50ms + 70ms = 120ms - 2nd function call
50 + 20 * 2 = 90 // 50ms + 70ms + 90ms = 210ms - 3rd function call
Python Solution
# TODO: add Python solution
Complexity
The time complexity is O(n). The space complexity is O(1) to O(n).
Edge Cases and Pitfalls
Watch for boundary values, empty inputs, and duplicate values where applicable. If the problem involves ordering or constraints, confirm the invariant is preserved at every step.
Summary
This Python solution focuses on the essential structure of the problem and keeps the implementation interview-friendly while meeting the constraints.