---
changelog:
  category: Release
  version: 20260824.202212.000000000
date: '2026-08-24T20:22:12Z'
seo:
  description: >-
    Finished Mon, Aug 24, 2026, 4:22 PM ET: all 4 core problems closed, 5
    problems closed that day. Scheduled: Mon Aug 24, 2026 · Phase: Phase I —
    Linear…
title: Topic 03 — Two Pointers
type: changelog
---
<!-- release-topics: #5 -->
Finished Mon, Aug 24, 2026, 4:22 PM ET: all 4 core problems closed, 5 problems closed that day.

**Scheduled:** Mon Aug 24, 2026 · **Phase:** Phase I — Linear Structures · **Topic:** #5 · **Builds on:** ordered iteration

## Closed Aug 24 — the day the topic finished

| Issue | Problem | Set | Difficulty | Closed (ET) | Solution |
| --- | --- | --- | --- | --- | --- |
| #41 | LC 125 · Valid Palindrome | core | easy | Aug 24 | [js](https://github.com/prdlk/leetcode/blob/20260824.202212.000000000/work/Easy/Two%20Pointers/125.valid-palindrome.js) · [docs](https://lc.prd.lk/125) |
| #42 | LC 167 · Two Sum II | core | medium | Aug 24 | [py](https://github.com/prdlk/leetcode/blob/20260824.202212.000000000/work/Medium/Array/167.two-sum-ii-input-array-is-sorted.py) · [docs](https://lc.prd.lk/167) |
| #43 | LC 15 · 3Sum | core | medium | Aug 24 | [py](https://github.com/prdlk/leetcode/blob/20260824.202212.000000000/work/Medium/Array/15.3sum.py) · [docs](https://lc.prd.lk/15) |
| #44 | LC 11 · Container With Most Water | core | medium | Aug 24 | [py](https://github.com/prdlk/leetcode/blob/20260824.202212.000000000/work/Medium/Array/11.container-with-most-water.py) · [docs](https://lc.prd.lk/11) |
| #46 | LC 977 · Squares of a Sorted Array | optional | easy | Aug 24 | [js](https://github.com/prdlk/leetcode/blob/20260824.202212.000000000/work/Easy/Array/977.squares-of-a-sorted-array.js) · [docs](https://lc.prd.lk/977) |

## Open at release

| Issue | Problem | Set | Difficulty | Closed (ET) | Solution |
| --- | --- | --- | --- | --- | --- |
| #45 | LC 392 · Is Subsequence | optional | easy | — | — |
| #47 | LC 189 · Rotate Array | optional | medium | — | — |
| #48 | LC 80 · Remove Duplicates II | optional | medium | — | — |

---

`20260824.202212.000000000` is [timever](https://gist.github.com/twolfson/de1b004dd22536b8e668) for the UTC instant the core set completed; it tags 2d37d6b, the last main commit before it.