给定一个数组 nums，编写一个函数将所有 0 移动到数组的末尾，同时保持非零元素的相对顺序。示例:输入: [0,1,0,3,12] 输出: [1,3,12,0,0] 说明:必须在原数组上操作，不能拷贝额外的数组。 尽量减少操作次数。说下拿到这道题时的思路： 给人的感觉并不难，首先的想法就是遍历数组中每一个元素，判断如果为0则删除，同时末尾增加0 上代码（通过240ms)击败20%的用户 1 class Solution:2 def moveZeroes(self, nums):3 """...
给定一个非空整数数组，除了某个元素只出现一次以外，其余每个元素均出现两次。找出那个只出现了一次的元素。说明：你的算法应该具有线性时间复杂度。 你可以不使用额外空间来实现吗？示例 1:输入: [2,2,1] 输出: 1 示例 2:输入: [4,1,2,1,2] 输出: 4 先说自己的思路 这题和217存在重复问题相似 这题找数组中只有一次的数字 而存在重复问题是找出现两次的数字 所以我先排序 然后以2为间隔两两进行对比 是否相同 如果不同则retur...
小编从今天起要开始分享一些Leedcode代码，通过好好练习编程能力，争取以后找一份好工作。题目：两数相加 # Definition for singly-linked list. # class ListNode: # def __init__(self, x): # self.val = x # self.next = Noneclass Solution:def addTwoNumbers(self, l1, l2):""":type l1: ListNode:type l2: ListNode:rtype: ListNode""" #l1.val表示当前链表的值，l...
原题 https://leetcode.com/problems/minesweeper/ 解法 DFS. Base case是board为空时, 返回[]. 定义DFS函数, base case是当前位置的值不是’E’, 直接返回. 我们先计算click位置的相邻位置有多少个’M’, 将click位置更新, 注意: 如果click位置更新的是数字的话, 我们就不再对它相邻的’E’进行reveal, 直接return. 如果click位置更新的是’B’的话, 我们用DFS进行递归. 代码 class Solution:def updateBoard(self, board, click)...
四种做法： 1.我不太懂的做法，来自评论：https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list/comments/ # Definition for singly-linked list. # class ListNode: # def __init__(self, x): # self.val = x # self.next = Noneclass Solution:def removeNthFromEnd(self, head, n):""":type head: ListNode:type n: int:rtype: ListNode"""tail = headprevious = headprior = headi = 1whil...
对每个字符串进行排序,那么排序后Anagrams的字符串是相同的 class Solution:def groupAnagrams(self, strs):""":type strs: List[str]:rtype: List[List[str]]"""dict1={}for i in range(len(strs)):strsort = ''.join(sorted(strs[i]))if not strsort in dict1:dict1[strsort]=[i]else:dict1[strsort].append(i)res=[]for list1 in dict1.values():temp=[]for index in list1:temp.append(strs[index])res.append(temp)return res
Design a HashSet without using any built-in hash table libraries. To be specific, your design should include these functions:add(value): Insert a value into the HashSet. contains(value) : Return whether the value exists in the HashSet or not. remove(value): Remove a value in the HashSet. If the value does not exist in the HashSet, do nothing.Example: MyHashSet hashSet = new MyHashSet(); hashSet.a...
We want to use quad trees to store an N x N boolean grid. Each cell in the grid can only be true or false. The root node represents the whole grid. For each node, it will be subdivided into four children nodes until the values in the region it represents are all the same. Each node has another two boolean attributes : isLeaf and val. isLeaf is true if and only if the node is a leaf node. The val a...
You need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way. The null node needs to be represented by empty parenthesis pair "()". And you need to omit all the empty parenthesis pairs that dont affect the one-to-one mapping relationship between the string and the original binary tree. Example 1: Input: Binary tree: [1,2,3,4]1/ 2 ...
给定一个二进制数组， 计算其中最大连续1的个数。 示例 1:输入: [1,1,0,1,1,1] 输出: 3 解释: 开头的两位和最后的三位都是连续1，所以最大连续1的个数是 3.注意： 输入的数组只包含 0 和1。 输入数组的长度是正整数，且不超过 10,000。 Cint findMaxConsecutiveOnes(int* nums, int numsSize) {int n=numsSize;int count=0;int res=0;for(int i=0;i<n;i++){if(1==nums[i]){count+=1;}else{res=res>count?res:count;count=0;}}retu...
Given a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target. Example 1: Input: 5/ 3 6/ \ 2 4 7Target = 9Output: True Example 2: Input: 5/ 3 6/ \ 2 4 7Target = 28Output: False# Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # ...
Given a word, you need to judge whether the usage of capitals in it is right or not. We define the usage of capitals in a word to be right when one of the following cases holds:All letters in this word are capitals, like "USA". All letters in this word are not capitals, like "leetcode". Only the first letter in this word is capital if it has more than one letter, like "Google".Otherwise, we define...
You are given a data structure of employee information, which includes the employees unique id, his importance value and his direct subordinates id. For example, employee 1 is the leader of employee 2, and employee 2 is the leader of employee 3. They have importance value 15, 10 and 5, respectively. Then employee 1 has a data structure like [1, 15, [2]], and employee 2 has [2, 10, [3]], and employ...
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构造法递归相似题目参考资料日期 题目地址：https://leetcode.com/problems/beautiful-array/description/ 题目描述 For some fixed N, an array A is beautiful if it is a permutation of the integers 1, 2, …, N, such that: For every i < j, there is no k with i < k < j such that A[k] * 2 = A[i] + A[j]. Given N, r...
有效的数字（简单题） class Solution:def isValid(self, s):""":type s: str:rtype: bool"""a=list(s)b=[] #存放左括号的栈 qc:list当做栈c={'(':')','[':']','{':'}'} #字典存储 qc；key:value 键：值for i in a:if i=='':return Trueelif i in c:#如果是字典中的键，即左括号，放进栈b.append(i)else:if len(b)==0: #先判断是否有左括号存在return Falseelse:#字典得到该键的值==栈顶值对应...