String (89 completed) Back to top # Title Level Cats Solution Languages Date Complete 3 Longest Substring Without Repeating Characters Medium B75, N150 solution java Jul 10, 2024 5 Longest Palindromic Substring Medium B75, N150 solution py Jul 10, 2024 8 String to Integer (atoi) Medium solution py Jul 10, 2024 14 Longest Common Prefix Easy solution java Jul 10, 2024 20 Valid Parentheses Easy B75, N150 solution java Jul 10, 2024 22 Generate Parentheses Medium N150 solution py Jul 10, 2024 28 Find the Index of the First Occurrence in a String Easy solution py Jul 10, 2024 49 Group Anagrams Medium B75, N150 solution py Jul 10, 2024 71 Simplify Path Medium solution py Jul 10, 2024 79 Word Search Medium B75, N150 solution py Jul 10, 2024 125 Valid Palindrome Easy B75, N150 solution c, py Jul 10, 2024 165 Compare Version Numbers Medium solution c, py Jul 10, 2024 166 Fraction to Recurring Decimal Medium solution py Jul 10, 2024 208 Implement Trie (Prefix Tree) Medium B75, N150 solution py Jul 10, 2024 211 Design Add and Search Words Data Structure Medium B75, N150 solution py Jul 10, 2024 212 Word Search II Hard B75, N150 solution py Jul 10, 2024 224 Basic Calculator Hard solution py Jul 10, 2024 227 Basic Calculator II Medium solution py Jul 10, 2024 242 Valid Anagram Easy B75, N150 solution c, py Jul 10, 2024 271 Encode and Decode Strings Medium B75, N150 solution py Jul 10, 2024 273 Integer to English Words Hard solution py Jul 10, 2024 344 Reverse String Easy Daily solution java, py Jul 10, 2024 345 Reverse Vowels of a String Easy solution py Jul 10, 2024 392 Is Subsequence Easy solution java Jul 10, 2024 394 Decode String Medium solution py Jul 10, 2024 408 Valid Word Abbreviation Easy solution py Jul 10, 2024 409 Longest Palindrome Easy Daily solution c, py Jul 10, 2024 412 Fizz Buzz Easy solution java, py Jul 10, 2024 424 Longest Repeating Character Replacement Medium B75, N150 solution py Jul 10, 2024 451 Sort Characters By Frequency Medium solution py Jul 10, 2024 535 Encode and Decode TinyURL Medium solution py Jul 10, 2024 567 Permutation in String Medium N150 solution py Jul 10, 2024 616 Add Bold Tag in String Medium solution py Jul 10, 2024 647 Palindromic Substrings Medium B75, N150 solution py Jul 10, 2024 648 Replace Words Medium Daily solution java, py Jul 10, 2024 676 Implement Magic Dictionary Medium solution py Jul 10, 2024 692 Top K Frequent Words Medium solution py Jul 10, 2024 720 Longest Word in Dictionary Medium solution py Jul 10, 2024 758 Bold Words in String Medium solution py Jul 10, 2024 771 Jewels and Stones Easy solution java, py Jul 10, 2024 784 Letter Case Permutation Medium solution py Jul 10, 2024 791 Custom Sort String Medium solution java Jul 10, 2024 848 Shifting Letters Medium solution py Jul 10, 2024 856 Score of Parentheses Medium solution py Jul 10, 2024 890 Find and Replace Pattern Medium solution py Jul 10, 2024 921 Minimum Add to Make Parentheses Valid Medium solution java, py Jul 10, 2024 1002 Find Common Characters Easy Daily solution py Jul 10, 2024 1028 Recover a Tree From Preorder Traversal Hard solution py Jul 10, 2024 1087 Brace Expansion Medium solution py Jul 10, 2024 1166 Design File System Medium solution py Jul 10, 2024 1209 Remove All Adjacent Duplicates in String II Medium solution py Jul 10, 2024 1233 Remove Sub-Folders from the Filesystem Medium solution py Jul 10, 2024 1239 Maximum Length of a Concatenated String with Unique Characters Medium solution py Jul 10, 2024 1249 Minimum Remove to Make Valid Parentheses Medium solution py Jul 10, 2024 1255 Maximum Score Words Formed by Letters Hard solution py Jul 10, 2024 1268 Search Suggestions System Medium solution py Jul 10, 2024 1404 Number of Steps to Reduce a Number in Binary Representation to One Medium Daily solution py Jul 10, 2024 1436 Destination City Easy solution java Jul 10, 2024 1455 Check If a Word Occurs As a Prefix of Any Word in a Sentence Easy solution py Jul 10, 2024 1525 Number of Good Ways to Split a String Medium solution py Jul 10, 2024 1598 Crawler Log Folder Easy Daily solution c, js Jul 10, 2024 1684 Count the Number of Consistent Strings Easy solution c, py Jul 10, 2024 1689 Partitioning Into Minimum Number Of Deci-Binary Numbers Medium solution c, java Jul 10, 2024 1698 Number of Distinct Substrings in a String Medium solution java, py Jul 10, 2024 1736 Latest Time by Replacing Hidden Digits Easy solution c Jul 10, 2024 1759 Count Number of Homogenous Substrings Medium solution c, java Jul 10, 2024 1768 Merge Strings Alternately Easy solution java Jul 10, 2024 1804 Implement Trie II (Prefix Tree) Medium solution py Jul 10, 2024 1844 Replace All Digits with Characters Easy solution py Jul 10, 2024 1980 Find Unique Binary String Medium solution c, py Jul 10, 2024 2011 Final Value of Variable After Performing Operations Easy solution c Jul 10, 2024 2083 Substrings That Begin and End With the Same Letter Medium Weekly Premium solution c, py Jul 10, 2024 2086 Minimum Number of Food Buckets to Feed the Hamsters Medium solution java Jul 10, 2024 2268 Minimum Number of Keypresses Medium solution py Jul 10, 2024 2390 Removing Stars From a String Medium solution java, py Jul 10, 2024 2405 Optimal Partition of String Medium solution py Jul 10, 2024 2423 Remove Letter To Equalize Frequency Easy solution py Jul 10, 2024 2486 Append Characters to String to Make Subsequence Medium Daily solution c, java, py Jul 10, 2024 2678 Number of Senior Citizens Easy solution java Jul 10, 2024 2734 Lexicographically Smallest String After Substring Operation Medium solution py Jul 10, 2024 2743 Count Substrings Without Repeating Character Medium Weekly Premium solution java, py Jul 10, 2024 2942 Find Words Containing Character Easy solution c Jul 10, 2024 3043 Find the Length of the Longest Common Prefix Medium solution py Jul 10, 2024 3045 Count Prefix and Suffix Pairs II Hard solution py Jul 10, 2024 3106 Lexicographically Smallest String After Operations With Constraint Medium solution py Jul 10, 2024 3110 Score of a String Easy Daily solution java, py Jul 10, 2024 3136 Valid Word Easy solution c, py Jul 10, 2024 3168 Weekly Contest 400 - q1 - Minimum Number of Chairs in a Waiting Room Easy Contest solution py Jul 10, 2024 3174 Biweekly Contest 132 - q1 - Clear Digits Easy Contest solution py Jul 10, 2024