An algorithm is a sequence of unambiguous steps to do a task. The challenges below require you to come up with algorithms to solve the problems.

Array
String
Dictionary
Dynamic Programming
Recursion
Tree

Valid Palindrome
Student Attendance Record I
Detect Capital
Valid Parentheses
Goat Latin
Implement strStr()
Positions of Large Groups
Longest Common Prefix
Long Pressed Name
Valid Palindrome II
Longest Palindromic Substring
Camelcase Matching