James Pan

原题网址：https://leetcode.com/problems/valid-anagram/Given two strings s and t, write a function to determine if t is an anagram of s.For example,s = "anagram", t = "nagaram", return true.s 

原题网址：https://leetcode.com/problems/substring-with-concatenation-of-all-words/You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of

原题网址：https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/Given a string, find the length of the longest substring T that contains at most k distinct characters.

原题网址：https://leetcode.com/problems/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 ex

原题网址:https://leetcode.com/problems/rearrange-string-k-distance-apart/Given a non-empty string str and an integer k, rearrange the string such that the same characters are at least distance k fro

原题网址：https://leetcode.com/problems/remove-duplicate-letters/Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You mus

原题网址：https://leetcode.com/problems/find-all-anagrams-in-a-string/Given a string s and a non-empty string p, find all the start indices of p's anagrams in s.Strings consists of lowercase Engl

原题网址：https://leetcode.com/problems/find-the-difference/Given two strings s and t which consist of only lowercase letters.String t is generated by random shuffling string s and then add one m

原题网址：https://leetcode.com/problems/ransom-note/Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the r

原题网址：https://leetcode.com/problems/first-unique-character-in-a-string/Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.Examp

原题网址：https://leetcode.com/problems/longest-palindrome/Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those let

原题网址：https://leetcode.com/problems/largest-rectangle-in-histogram/Given n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest

原题网址：https://leetcode.com/problems/scramble-string/Given a string s1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible

原题网址：https://leetcode.com/problems/maximal-rectangle/Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.方法：应用直方图最大矩形面积的方法。publ

原题网址：https://leetcode.com/problems/palindrome-permutation/Given a string, determine if a permutation of the string could form a palindrome.For example,"code" -> False, "aab" -> True, "ca

原题网址：https://leetcode.com/problems/bulls-and-cows/You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. E

原题网址：https://leetcode.com/problems/longest-substring-without-repeating-characters/Given a string, find the length of the longest substring without repeating characters.Examples:Given "ab

原题网址：https://leetcode.com/problems/isomorphic-strings/Given two strings s and t, determine if they are isomorphic.Two strings are isomorphic if the characters in s can be replaced to get t.

原题网址：https://leetcode.com/problems/maximum-product-of-word-lengths/Given a string array words, find the maximum value of length(word[i]) * length(word[j]) where the two words do not share comm

原题网址：https://leetcode.com/problems/maximal-square/Given a 2D binary matrix filled with 0's and 1's, find the largest square containing all 1's and return its area.For example, given the foll

原题网址：https://leetcode.com/problems/container-with-most-water/Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn su

原题网址：https://leetcode.com/problems/substring-with-concatenation-of-all-words/You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of

原题网址：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 fil

原题网址：https://leetcode.com/problems/sudoku-solver/Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character '.'.You may assume that th

原题网址：https://leetcode.com/problems/anagrams/Given an array of strings, group anagrams together.For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return:[ ["ate", "eat","t

原题网址：https://leetcode.com/problems/sort-characters-by-frequency/Given a string, sort it in decreasing order based on the frequency of characters.Example 1:Input:"tree"Output:"eert"Ex