Three Pointers, One Pass: The Dutch Flag Algorithm Decoded

The Dutch Flag Algorithm teaches a powerful partitioning pattern frequently asked in coding interviews: how to segregate an array in one pass without extra space. This technique reveals how multiple pointers can elegantly transform a counting-based solution into an optimal in-place algorithm, achieving O(N) time and O(1) space. Mastering this pattern is essential for interview success and demonstrates the importance of questioning if a straightforward approach can be optimized further.