05 2015 档案
摘要：Find all possible combinations ofknumbers that add up to a numbern, given that only numbers from 1 to 9 can be used and each combination should be a u...
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摘要：Find thekth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element.For exampl...
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摘要：Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can f...
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摘要：Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.思路：注意，在for循环中条件有计算得到的负数时, ...
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摘要：Roman to IntegerGiven a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.思路：首先要学一下罗马数字是怎么表示的，参见百度百科其实...
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摘要：There are a total ofncourses you have to take, labeled from0ton - 1.Some courses may have prerequisites, for example to take course 0 you have to firs...
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摘要：Reverse a singly linked list.思路：没啥好说的。秒...ListNode* reverseList(ListNode* head) { ListNode * rList = NULL, * tmp = NULL; while(head != N...
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摘要：Given two stringssandt, determine if they are isomorphic.Two strings are isomorphic if the characters inscan be replaced to gett.All occurrences of a ...
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摘要：Count the number of prime numbers less than a non-negative number,n思路：数质数的个数开始写了个蛮力的，存储已有质数，判断新数字是否可以整除已有质数。然后妥妥的超时了(⊙v⊙)。看提示，发现有个Eratosthenes算法找质数的，说...
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摘要：Given a 2D board and a list of words from the dictionary, find all words in the board.Each word must be constructed from letters of sequentially adjac...
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摘要：Given a set ofnon-overlappingintervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially...
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摘要：Given an array ofnpositive integers and a positive integers, find the minimal length of a subarray of which the sum ≥s. If there isn't one, return 0 i...
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摘要：The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ...1is read off as"one 1"or11.11is read off as"tw...
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摘要：Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth...
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摘要：Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only n...
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摘要：Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened t...
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摘要：Write an algorithm to determine if a number is "happy".A happy number is a number defined by the following process: Starting with any positive integer...
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摘要：Remove all elements from a linked list of integers that have valueval.ExampleGiven:1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6,val= 6Return:1 --> 2 --> 3 --...
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摘要：Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations:getandset.get(key)- Get the valu...
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摘要：应小伙伴的要求，做一个小计时器。功能是点击开始就从00:00:00开始计时，点击暂停就暂停计时，点击停止就停止计时。界面如上图，使用ui设计师直接拖的。按钮和图标的图片都是网上下载的。用美图秀秀抠成了透明的，看起来会好看一点。整体代码挺容易的，就是设一个定时器。代码如下：mainwindow.h#i...
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摘要：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...
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摘要：Compare two version numbersversion1andversion2.Ifversion1>version2return 1, ifversion1 n2) return 1; if(n1 n2) return 1; else if(n1...
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摘要：Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B 3 -> C ... 26 ->...
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摘要：Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Callingnext()will return the next...
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摘要：Given a 2d grid map of'1's (land) and'0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent ...
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摘要：Given a 2D board containing'X'and'O', capture all regions surrounded by'X'.A region is captured by flipping all'O's into'X's in that surrounded region...
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摘要：Evaluate the value of an arithmetic expression inReverse Polish Notation.Valid operators are+,-,*,/. Each operand may be an integer or another express...
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