# Partition Equal Subset Sum
Given a list of positive integers, return whether it can be split into two subsets with equal sums.
This is 0/1-knapsack in disguise (Module 2's DP lesson) — a distinct DP family from every problem Mock 5 already tests (Fibonacci-shaped Climbing Stairs, unbounded-coin Coin Change, LIS, substring-DP Word Break); none of those touch subset-sum/knapsack.
**Example:** `[1,5,11,5]` -> `True` (`[1,5,5]` and `[11]` both sum to 11).
Target complexity: O(N * sum).