u014142015的博客

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] 

Given a singly linked list, determine if it is a palindrome.Follow up:Could you do it in O(n) time and O(1) space?这个题目在discussion里有人证明了空间复杂度不可能为O(1)。/** * Definition for singly-linked list.

这个题是把链表进行重新排序，先把奇数节点放在一起，再把偶数节点放在一起。需要注意： odd_node->next = NULL 要写上，否则会出现错误** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode

Given a (singly) linked list with head node root, write a function to split the linked list into k consecutive linked list "parts".The length of each part should be as equal as possible: no two

Reverse a linked list from position m to n. Do it in-place and in one-pass.For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4,return 1->4->3->2->5->NULL.Note:Given m, n satisfy the

Write a program to find the node at which the intersection of two singly linked lists begins.For example, the following two linked lists:A: a1 → a2 ↘

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. Y

Given a linked list, remove the nth node from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the

Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…You must do this in-place without altering the nodes' values.For example,Given {1,2,3,4}, reorder it t

Remove all elements from a linked list of integers that have value val.ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6Return: 1 --> 2 --> 3 --> 4 --> 5Credits:Special than

Given a sorted linked list, delete all duplicates such that each element appear only once.For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3, return 1->2->3.需要注意只存在一个节点的情况，/** 

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.For this problem, a height-balanced binary tree is defined as a binary tree in which th

Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.k is a positive integer and is less than or equal to the length of the linked list. If the number o

Given a binary tree, return the vertical order traversal of its nodes' values. (ie, from top to bottom, column by column).If two nodes are in the same row and column, the order should be from left

Given a list of daily temperatures, produce a list that, for each day in the input, tells you how many days you would have to wait until a warmer temperature. If there is no future day for which thi

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed).Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top

Given a time represented in the format "HH:MM", form the next closest time by reusing the current digits. There is no limit on how many times a digit can be reused.You may assume the given input str

133:/** * Definition for undirected graph. * struct UndirectedGraphNode { *     int label; *     vector neighbors; *     UndirectedGraphNode(int x) : label(x) {}; * }; */class Soluti

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    Li

很好的一个模板题，链表找中点（快慢指针）和merge。/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */clas

Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.Your task is to find the smallest possible length o

560. Subarray Sum Equals KGiven an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k.Example 1:Input:nums = [1,1,1], k

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up t

Given an array of integers nums, write a method that returns the "pivot" index of this array.We define the pivot index as the index where the sum of the numbers to the left of the index is equal t

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.Example:Given a = 1 and b = 2, return 3.00 + 00->0000 + 01-> 0101 + 00-> 0101 + 01-> 10cl

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.Note: The result may be ve

Find the largest palindrome made from the product of two n-digit numbers.Since the result could be very large, you should return the largest palindrome mod 1337.Example:Input: 2Output:

Implement pow(x, n).Example 1:Input: 2.00000, 10Output: 1024.00000Example 2:Input: 2.10000, 3Output: 9.26100class Solution {public: double myPow(double x, int n) {

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

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:[ "((()))", "(()())", "(())()", "()(())

During the NBA playoffs, we always arrange the rather strong team to play with the rather weak team, like make the rank 1 team play with the rank nth team, which is a good strategy to make the conte

Given an absolute path for a file (Unix-style), simplify it.For example,path = "/home/", => "/home"path = "/a/./b/../../c/", => "/c"Corner Cases:Did you consider the case where p

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return

You are given two non-empty linked lists representing two non-negative integers. The most significant digit comes first and each of their nodes contain a single digit. Add the two numbers and return i

Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2.Note:The length of both num1 and num2 is Both num1 and num2 contains only digits

这个题很简单，仅此记录一下；class Solution {public:    string addStrings(string num1, string num2) {        int size1 = num1.size();        int size2 = num2.size();        string res = "";        int