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 substring(s) in s that is a concatenation of each word in wo…

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&q…

You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in words exactly once and without any intervening characters. For example, giv…

其他LeetCode题目欢迎访问:LeetCode结题报告索引 LeetCode:Word Ladder Given two words (start and end), and a dictionary, find the length of shortest transformation sequence from start to end, such that: Only one letter can be changed at a time Each intermediate word…

Given a set of words (without duplicates), find all word squares you can build from them. A sequence of words forms a valid word square if the kth row and column read the exact same string, where 0 ≤ k < max(numRows, numColumns). For example, the wor…

Id Question Difficulty Frequency Data Structures Algorithms 1 Two Sum 2 5 array + set sort + two pointers 2 Add Two Numbers 3 4 linked list two pointers + math 3 Longest Substring Without Repeating Characters 3 2 string + hashtable two pointers 4 Med…

题目: Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the difference between i and jis at most k. 给定一个整形数组和一个整数型数k,找出在这个数组中是否存在两个相同的数,并且这两个数的下标的距离小于k. "&q…

转自  http://tech-wonderland.net/blog/summary-of-ksum-problems.html 前言: 做过leetcode的人都知道, 里面有2sum, 3sum(closest), 4sum等问题, 这些也是面试里面经典的问题, 考察是否能够合理利用排序这个性质, 一步一步得到高效的算法. 经过总结, 本人觉得这些问题都可以使用一个通用的K sum求和问题加以概括消化, 这里我们先直接给出K Sum的问题描述和算法(递归解法), 然后将这个一般性的方法套用…

1 题目 Description: Count the number of prime numbers less than a non-negative number, n. 接口:public int countPrimes(int n); 2 思路 统计小于n的素数个数,注意不包括n. 思路1:素数的判断 很容易想到素数的判断isPrime,然后逐个数来进行判断是否是素数.进行统计,输出结果. 复杂度: 把isPrime时间复杂度控制在O(n^0.5)的话,因此:Time:O(n^1.5)…

1 题目 Contains Duplicate I Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct. 接口: public bo…