Click4Ai

20.

Medium

Write a function find_outliers(arr) that identifies outlier values in an array using the IQR (Interquartile Range) method.

IQR Method:

1. Sort the data and find Q1 (25th percentile) and Q3 (75th percentile)

2. IQR = Q3 - Q1

3. Lower bound = Q1 - 1.5 * IQR

4. Upper bound = Q3 + 1.5 * IQR

5. Any value outside [lower, upper] is an outlier

Example:

Input: arr = [1, 2, 3, 4, 5, 100, 6, 7, 8, -50]

Output: [100, -50]

Constraints:

  • Array length: 4 <= len(arr) <= 1000
  • Return a sorted list of outlier values
  • Use numpy's percentile for Q1 and Q3

    • Test Cases

    Test Case 1
    Input: [1, 2, 3, 4, 5, 100, 6, 7, 8, -50]
    Expected: [-50, 100]
    Test Case 2
    Input: [1, 2, 3, 4, 5]
    Expected: []
    Test Case 3
    Input: [10, 10, 10, 10, 50]
    Expected: [50]
    + 2 hidden test cases