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DSA SectionEasy

Wave Form Sorting

Learn how to solve the 'Wave Form Sorting' problem. This detailed resource details brute force and optimized approaches.

Problem Statement

Easy

Write a function wave_sort(arr) that sorts an array of integers arr in place or returns a sorted version in wave form, such that arr[0] >= arr[1] <= arr[2] >= arr[3] <= arr[4]....

Constraints
  • 1 <= len(arr) <= 1000
  • -10^4 <= arr[i] <= 10^4

Examples

Example 1
Input
arr = [10, 5, 6, 3, 2, 20, 100, 80]
Output
[10, 5, 6, 2, 20, 3, 100, 80]
Explanation

The output elements satisfy wave pattern: 10 >= 5 <= 6 >= 2 <= 20 >= 3 <= 100 >= 80.

Need a Hint?
Analyze the input constraints. Try sorting first (O(n log n)) or using a hash map/set to track seen elements in O(n) time.
Edge Cases to Watch
  • Empty list or null input variables
  • Single item lists/arrays
  • Extremely large input bounds causing integer or stack overflow

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