Problems

12 problems

• Easy

  Valid Anagram

  Given two strings s and t, return true if t is an …

  Hashing Strings
• Easy

  Valid Palindrome

  Given a string s, return true if it is a palindrome, or …

  Strings Two Pointers
• Easy

  First Unique Character in a String

  Return index of first non-repeating character, else -1.

  Hashing Strings
• Medium

  Longest Palindromic Substring Length

  Return the length of the longest palindromic substring.

  Dynamic Programming Strings
• Medium

  Partition Labels

  Partition string so each letter appears in at most one part; return …

  Greedy Strings
• Medium

  Decode String

  Decode strings encoded as k[encoded_string].

  Stack Strings
• Medium

  Word Break

  Return true if s can be segmented into dictionary words.

  Dynamic Programming Strings
• Medium

  Decode Ways

  Return number of ways to decode the string.

  Dynamic Programming Strings
• Hard

  Minimum Window Substring

  Return the minimum window in s that contains all chars of t.

  Sliding Window Strings
• Hard

  Edit Distance

  Return minimum number of operations to convert word1 to word2.

  Dynamic Programming Strings
• Hard

  Distinct Subsequences

  Return number of distinct subsequences of s that equal t.

  Dynamic Programming Strings
• Hard

  Regular Expression Matching

  Implement regex matching with support for '.' and '*'.

  Dynamic Programming Strings