题目: Given an array of strings, return all groups of strings that are anagrams. Note: All inputs will be in lower-case. 题解: 这道题看所给的字符串数组里面有多少个是同一个变形词变的.这道题同样使用HashMap来帮助存老值和新值,以及帮忙判断是否是变形词. 首先对每个string转换成char array然后排下序,HashMap里面的key存sort后的词,value存原始的…

目录 题目链接 注意点 解法 小结 题目链接 Group Anagrams - LeetCode 注意点 字母都是小写的 解法 解法一:用一个字符串表示strs[i]中出现的字母,比如:abc->111000000000000000000000000.aab->210000000000000000000000000.同时用map保存hash与vector的下标对应关系.时间复杂度O(n) class Solution { public: vector<vector<string&g…

题目: Follow up for N-Queens problem. Now, instead outputting board configurations, return the total number of distinct solutions. 题解: 这道题跟NQueens的解法完全一样(具体解法参照N QueensN Queens leetcode java),只不过要求的返回值不同了..所以要记录的result稍微改一下就好了... 因为涉及到递归,result传进去引用类型(…

题目: Implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial). The function prototype shoul…

Reference: http://blog.csdn.net/lbyxiafei/article/details/9375735  题目: Implement int sqrt(int x). Compute and return the square root of x. 题解: 这道题很巧妙的运用了二分查找法的特性,有序,查找pos(在这道题中pos=value),找到返回pos,找不到返回邻近值. 因为是求数x(x>=0) 的平方根, 因此,结果一定是小于等于x且大于等于0,所以用二分查…

Question 49. Group Anagrams Solution 思路:维护一个map,key是输入数组中的字符串(根据字符排好序) Java实现: public List<List<String>> groupAnagrams(String[] strs) { Map<String, List<String>> map = new HashMap<>(); for (String str : strs) { String key = g…

题目: The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNAP…

Candy There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following requirements: Each child must have at least one candy. Children with a higher rating get more ca…

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"A man, a plan, a canal: Panama" is a palindrome."race a car" is not a palindrome. Note:Have you consider that th…

Given an array of strings, return all groups of strings that are anagrams. Note: All inputs will be in lower-case. Summary: To sort and compare strings, using map to record distinct strings. class Solution { public: vector<string> anagrams(vector<…