Two Pointers (54 completed) Back to top # Title Level Cats Solution Languages Date Complete 5 Longest Palindromic Substring Medium B75, N150 solution py Jul 05, 2024 19 Remove Nth Node From End of List Medium B75, N150 solution c, java, py Jun 07, 2024 26 Remove Duplicates from Sorted Array Easy solution java May 22, 2024 27 Remove Element Easy solution java, py Jun 02, 2024 28 Find the Index of the First Occurrence in a String Easy solution py May 22, 2024 61 Rotate List Medium solution py Jun 22, 2024 75 Sort Colors Medium Daily solution c, py Jun 12, 2024 82 Remove Duplicates from Sorted List II Medium solution py Jul 04, 2024 125 Valid Palindrome Easy B75, N150 solution c, py Jun 07, 2024 141 Linked List Cycle Easy B75, N150 solution c, py Jun 04, 2024 142 Linked List Cycle II Medium solution py Jun 26, 2024 143 Reorder List Medium B75, N150 solution java, py Jun 11, 2024 165 Compare Version Numbers Medium solution c, py Jul 02, 2024 167 Two Sum II - Input Array Is Sorted Medium N150 solution py Jun 14, 2024 170 Two Sum III - Data structure design Easy solution py Jul 31, 2024 189 Rotate Array Medium solution py Jun 02, 2024 251 Flatten 2D Vector Medium solution py May 22, 2024 272 Closest Binary Search Tree Value II Hard solution py Jul 01, 2024 287 Find the Duplicate Number Medium N150 solution c Jun 26, 2024 344 Reverse String Easy Daily solution java, py Jun 02, 2024 345 Reverse Vowels of a String Easy solution py May 23, 2024 350 Intersection of Two Arrays II Easy Daily solution java, py Jul 02, 2024 392 Is Subsequence Easy solution java Jun 22, 2024 408 Valid Word Abbreviation Easy solution py Jun 02, 2024 475 Heaters Medium solution py Jun 07, 2024 567 Permutation in String Medium Daily, N150 solution py Jul 06, 2024 611 Valid Triangle Number Medium solution py May 22, 2024 647 Palindromic Substrings Medium B75, N150 solution py Jul 05, 2024 653 Two Sum IV - Input is a BST Easy solution py Jul 31, 2024 719 Find K-th Smallest Pair Distance Hard Daily solution py Aug 14, 2024 826 Most Profit Assigning Work Medium Daily solution py Jun 18, 2024 977 Squares of a Sorted Array Easy solution py Jun 21, 2024 1229 Meeting Scheduler Medium Weekly Premium solution py Sep 10, 2024 1265 Print Immutable Linked List in Reverse Medium solution c, py Jun 06, 2024 1455 Check If a Word Occurs As a Prefix of Any Word in a Sentence Easy solution py Jun 01, 2024 1508 Range Sum of Sorted Subarray Sums Medium Daily solution py Aug 04, 2024 1570 Dot Product of Two Sparse Vectors Medium solution c, java, py Jun 06, 2024 1634 Add Two Polynomials Represented as Linked Lists Medium Weekly Premium solution py Sep 06, 2024 1650 Lowest Common Ancestor of a Binary Tree III Medium solution py Jun 10, 2024 1721 Swapping Nodes in a Linked List Medium solution c Jun 07, 2024 1768 Merge Strings Alternately Easy solution java Jul 01, 2024 1877 Minimize Maximum Pair Sum in Array Medium solution py Jun 23, 2024 1885 Count Pairs in Two Arrays Medium solution py Jun 08, 2024 2046 Sort Linked List Already Sorted Using Absolute Values Medium solution py Jul 04, 2024 2095 Delete the Middle Node of a Linked List Medium solution c, java Jun 07, 2024 2130 Maximum Twin Sum of a Linked List Medium solution py Jun 21, 2024 2149 Rearrange Array Elements by Sign Medium solution c, py Jun 10, 2024 2396 Strictly Palindromic Number Medium solution c, cpp, java, js, kt, py, rb, rs Jun 09, 2024 2486 Append Characters to String to Make Subsequence Medium Daily solution c, java, py Jun 03, 2024 2570 Merge Two 2D Arrays by Summing Values Easy solution c Jun 10, 2024 3186 Weekly Contest 402 - q3 - Maximum Total Damage With Spell Casting Medium Contest solution py Jul 07, 2024 3194 Weekly Contest 403 - q1 - Minimum Average of Smallest and Largest Elements Easy Contest solution py Jul 07, 2024 3239 Biweekly Contest 136 - q2 - Minimum Number of Flips to Make Binary Grid Palindromic I Medium Contest solution py Aug 03, 2024 3240 Biweekly Contest 136 - q3 - Minimum Number of Flips to Make Binary Grid Palindromic II Medium Contest solution py Aug 03, 2024