Eliza1130的专栏

题目：Reverse digits of an integer.Have you thought about this?Here are some good questions to ask before coding. Bonus points for you if you have already thought through this!If the inte

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 NA P L S I

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum./** * Definition for binary tree * struct Tree

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.You may assume that the array is non-empty and the majority element

Given a positive integer, return its corresponding column title as appear in an Excel sheet.class Solution {public: string convertToTitle(int n) { string s; while(n){

Given numRows, generate the first numRows of Pascal's triangle.class Solution {public: vector > generate(int numRows) { vector> rs; if (numRows<=0){ return rs;

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top() -- Get

链表的归并排序特别注意取中值函数的书写/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {

Given a list of non negative integers, arrange them such that they form the largest number.For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.两两比较 可以利用sort函数来排序，自定义comp

Compare two version numbers version1 and version2.If version1 > version2 return 1, if version1 version2 return -1, otherwise return 0.class Solution {public: int compareVersion(string ver

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue.Here, we will use the integers

Sort a linked list using insertion sort.举例子真是写对代码的好方法！/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NU

判断是否为二叉搜索树定义上下确界/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} *

Given n, generate all structurally unique BST's (binary search trees) that store values 1...n.For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3

Reverse bits of a given 32 bits unsigned integer.归并法class Solution {public: uint32_t reverseBits(uint32_t n) { n=(n>>16)|(n<<16); n=((n&0xff00ff00)>>8)|((n&0x00ff00ff)<<8);

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 va

题目：Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical and the nodes have the same value.刷题打卡中

题目：Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (i

题目：Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?这是一道关于链表比较简单的题，很顺利就解决了，不多说啦，上代码啦# Definition for singly-linked list.#

题目：Given n, how many structurally unique BST's (binary search trees) that store values 1...n?For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2

题目：Given a binary tree, return the preorder traversal of its nodes' values.此题即为二叉树的前序遍历，递归的方法很简单：先节点再左子树再右子树；迭代的方法可以利用栈存储来完成遍历过程。补充递归与迭代的区别：许多问题是以递归的形式进行解释的，这只是因为它比非递归形式更为清晰。但是，这些问题的迭代往往比递归实现效率更

同num8一样，此题考查的是二叉树的中序遍历，即先左子树再节点再右子树、使用迭代法时，采用将节点和左子树均压入栈的方法，当左子树为NULL时，将top节点弹出，并存入结果列表，将next指针指向该节点的右节点代码如下：/** * Definition for binary tree * struct TreeNode { * int val; * Tre

题目：Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.Initially, all next pointers are set to NULL.You may

题目：Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicates in t

好久没有做题啦，从今天开始刷Leetcode的题，希望坚持的时间能长一点。先从ac率最高的Single Number开始吧。题目：Given an array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should hav

题目：Given a sorted linked list, delete all duplicates such that each element appear only once.这道链表的题也比较简单，目标是为了去重，只是需要注意在去重的过程中需要使用while循环，使一个节点的下一个节点必须指向与其不同的节点上代码咯# Definition for singly-li

题目：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?很简单的思路，因为一次可以走1~2步，所以

题目：Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.题目意思很简单，即将一个罗马数字的字符串，转化为整数。首先我们需要对罗马数字有一个基本的认识，由于题目已将数字大小限定在1~3999,所以我们只需考虑

题目：Find the contiguous subarray within an array (containing at least one number) which has the largest sum.For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1]

题目：Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.AC率第二高的题啦，二项树的最长路径。初看此题

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \3 4 4 3But the f