Practice/Netflix/Error Rate Monitor

Error Rate Monitor

CodingMust

Problem Overview

You are monitoring a system's error rates over time. Given an array errorRates where errorRates[i] represents the error rate at time i, determine if the system is healthy at a specific time point.

The system is considered healthy if ALL error rates within a time window are strictly below the given threshold (not equal to or above).

The time window is defined as [timePoint - timeRange, timePoint + timeRange] (inclusive). Only consider valid indices within the array bounds.

This is a straightforward array range query problem that tests boundary handling and comparison logic.

Example 1

` errorRates = [1, 3, 2, 5, 4, 2, 1] timePoint = 3 timeRange = 2 threshold = 6

Window: [3 - 2, 3 + 2] = [1, 5]

Indices 1 to 5 inclusive

Values: [3, 2, 5, 4, 2]

All values < 6? Yes

Output: true

`

Example 2

` errorRates = [1, 3, 2, 5, 4, 2, 1] timePoint = 3 timeRange = 2 threshold = 4

Window: [1, 5]

Values: [3, 2, 5, 4, 2]

All values < 4? No (5 and 4 are not strictly below 4)

Output: false

`

Example 3

` errorRates = [1, 2, 3] timePoint = 0 timeRange = 1 threshold = 5

Window: [0 - 1, 0 + 1] = [-1, 1]

Valid indices after clipping: [0, 1]

Values: [1, 2]

All values < 5? Yes

Output: true

`

Requirements

• Handle arrays up to length 10^5 efficiently
• Error rates can be from 0 to 10^4
• Properly clip the window to array bounds
• Use strict inequality (value must be strictly less than threshold)
• The threshold value itself is not acceptable

Clarification Questions to Ask

• Should we handle negative timePoint or timeRange values?
• Is it guaranteed that timePoint is a valid index in the array?
• What should we return for an empty window (though this shouldn't happen given constraints)?