27. Remove Element Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed.…

1.题目 27. Remove Element——Easy Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1)…

LeetCode第27题 Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The…

24. Swap Nodes in Pairs Given a linked list, swap every two adjacent nodes and return its head. For example,Given 1->2->3->4, you should return the list as 2->1->4->3. Your algorithm should use only constant space. You may not modify the…

14. Longest Common Prefix Write a function to find the longest common prefix string amongst an array of strings. 注:这题竟然连个示例都没有,说明特殊情况并不多,就是要找出所有字符串的最长公共前缀.他应该不会超过所有字符串中最短的那个,可以试着找出最短长度n,然后每个都读取和比较n个,并根据情况不断减小那个n.\ ) { return ""; } int n{int(strs…

题目 Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 分析 这是一道很简单的题目,对数组进行一次遍历,删除与给定值相等的关键字,返回新长度即可. AC代码 cla…

You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top? Note: Given n will be a positive integer. 对这种题目开始没有什么思路,借鉴博客http://blog.csdn.net/ken…

problem: Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 将一个数组里的和给定元素相同的元素删除,在该数组里操作,返回剩下的个数.注意,数组的前部分要保留…

Given an array nums and a value val, remove all instances of that value in-placeand return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of elem…

解法一:Brute-force int strStr(string haystack, string needle) { int m = haystack.size(); int n = needle.size(); if (!n) ; ; i < m - n + ; ++i) { ; while (j < n) { if (needle[j] == haystack[k]) { j++; k++; } else { break; } } if (j == n) return i; } ; }…

这道题跟26题很类似,并且有官方的答案.看了官方的答案之后发现写得特别巧,自己做的题太少思路太窄.有意思的是我的算法的时间复杂度是O(N^2),官方的是O(N),我的实际运行时间还少了2ms. iven an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must…

Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of ele…

Sqrt(x) Implement int sqrt(int x). Compute and return the square root of x. 注:这里的输入输出都是整数说明不会出现 sqrt(7)这种情况,思路一就是应用二分法进行查找.每次给出中间值,然后比对cur的平方与目标值的大小.需要先设定两个变量用来存放左右游标. 这里要考虑一下整型溢出的问题,另外,即使不能开出整数的也要近似给出整数部分,不能忽略. 代码如下: int Solution::mySqrt(int x) { //…

9. Palindrome Number Determine whether an integer is a palindrome. Do this without extra space. click to show spoilers. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the res…

今天的两道题关于基本数据类型的探讨,估计也是要考虑各种情况,要细致学习 7. Reverse Integer Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if…

1. Two Sum Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution. Example: Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + n…

#-*- coding: UTF-8 -*- class Solution(object):    def removeElement(self, nums, val):        """        :type nums: List[int]        :type val: int        :rtype: int        """        for i in range(len(nums)-1,-1,-1):      …

368. Largest Divisible Subset 题意:找到所有元素都不同的数组中满足以下规则的最大子集,规则为:子集中的任意两个元素a和b,满足a%b=0或者b%a=0. 解答:利用动态规划法求解.先给数组排好序.定义dp[i]表示以nums[i]结尾的子集的大小,则dp[i+1]=dp[j]+1,if nums[i+1]%nums[j]==0, 0<=j<=i,或者dp[i+1]=1.时间复杂度为O(n2). 代码如下: public List<Integer> la…

38. Count and Say The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11. 11 is read off as "two 1s" or 21. 21 is read off as "one 2, then one 1&quo…

20. Valid Parentheses Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]&quo…

1. Two Sum Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution. Example: Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + n…

题目要求:Remove Element Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 代码如下: class Solution { public: int re…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02): The signature of the function had been updated to return the index instead of the pointer. If you still…

Remove Element算是LeetCode的一道水题,不过这题也有多种做法,现就我所知的几种做一点讨论. 题目链接:https://leetcode.com/problems/remove-element/ 题目描述:Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. I…

Github leetcode 我的解题仓库   https://github.com/interviewcoder/leetcode 题目: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02):The signature of the function ha…

一天一道LeetCode系列 (一)题目 Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. (二)解题 第一种解法:朴素匹配算法 /* 两个指针,分别指向两个字符串的首字符 如果相等则一起向后移动,如果不同i取第一个相同字符的下一个开始继续匹配 如果最后j等于needle的长度则匹配成功,返回i-…

https://leetcode.com/problems/implement-strstr/ 题目: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 思路: 判断一个string是否另一个string的子序列并返回位置. naive法:遍历查找,复杂度O(mn). advance法还有Rabi…

Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Input: haystack = "hello", needle = "ll" Output: 2 Example 2: Input: haystack = "aaaaa",…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 find函数 遍历+切片 日期 题目地址:https://leetcode.com/problems/implement-strstr/description/ 题目描述 Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 注:直接看题目可能会有些偏差,因为容易认为 needle是一个字符,那就也太容易了,实则,haystack和needle都是字符串(注意是字符串不是数组) 解法思路: 暴力搜索: public class Solution { public int…