Algorithms-solutions Problem name Difficulty Languages LeetCode Unique Paths link Unique Paths II link Unique Binary Search Trees II link Unique Binary Search Trees link Ugly Number link Ugly Number II link UTF-8 Validation link Unique Substrings in Wraparound String link Unique Morse Code Words link Uncommon Words from Two Sentences link Unique Email Addresses link Univalued Binary Tree link Unique Paths III link Uncrossed Lines link Ugly Number III link Unique Number of Occurrences link Unique Length-3 Palindromic Subsequences link