76. Minimum Window Substring [https://leetcode.com/problems/minimum-window-substring/] LintCode-32.Minimum Window Substring [http://www.lintcode.com/en/problem/minimum-window-substring/] Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). For example, S = "ADOBECODEBANC"
246. Strobogrammatic Number [https://leetcode.com/problems/strobogrammatic-number/description/] A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down). Write a function to determine if a number is strobogrammatic. The number is represented as a string. For example, the numbers "69", "88"
358. Rearrange String k Distance Apart [https://leetcode.com/problems/rearrange-string-k-distance-apart/] Given a non-empty string s and an integer k, rearrange the string such that the same characters are at least distance k from each other. All input strings are given in lowercase letters. If it is not possible to
36. Valid Sudoku [https://leetcode.com/problems/valid-sudoku/] Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled with the character '.'. Note: A valid Sudoku board (partially filled) is not necessarily solvable. Only
LintCode-171.Anagrams [http://www.lintcode.com/en/problem/anagrams/] > Given an array of strings, return all groups of strings that are anagrams. > Notice: All inputs will be in lower-case. > Example > Given ["lint", "intl", "inlt", "code"], return ["lint", "inlt", "intl"]. > Given ["ab", "ba", "cd", "dc", "e"], return ["ab", "ba", "cd", "dc"