Sort 0s, 1s, 2s

Introduction Sorting an array containing only 0s, 1s, and 2s is a common problem in data structures. It is also known as the Dutch National Flag problem. Problem Statement Given an array containing only 0s, 1s, and 2s, sort the array in ascending order without using extra space. Approach (Dutch National Flag Algorithm) We use three pointers: low → for 0s mid → for traversal high → for 2s Steps: If element is 0 → swap with low and move both low and mid If element is 1 → move mid If element is 2 → swap with high and move high Python Code python def sort_colors(arr): low = 0 mid = 0 high = len(arr) - 1 while mid <= high: if arr[mid] == 0: arr[low], arr[mid] = arr[mid], arr[low] low += 1 mid += 1 elif arr[mid] == 1: mid += 1 else: # arr[mid] == 2 arr[mid], arr[high] = arr[high], arr[mid] high -= 1 return arr # Example arr = [2, 0, 2, 1, 1, 0] print("Sorted Array:", sort_colors(arr)) ## Input [2, 0, 2, 1, 1, 0] ## output [0, 0, 1, 1, 2, 2]