136. Single Number Given an array of integers, every element appears twice except for one. Find that single one. (Easy) Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 分析: 第一问属于技巧题,做过就会,…

题目: Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 中文(给定一个整数的数组,每个整数都出现了两次,只有一个出现了一次,找到它  建…

Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? Example 1: Input: [2,2,1] Output:…

题意:数组中每个数字都出现了两次,只有一个出现一次,找出这个数 思路:很明显不能从头到位遍历来找,首先是超时的原因,再次就是这样很没意思·····但是却没想到什么好办法,因为不了解按位异或(XOR).异或就是相同的两个数结果为0,不同的为1.根据交换律我们知道,数组中两两异或的结果就剩最后那一个落单的数了,因为两个相同的数异或结果为0.所以其实这题就很简单了,只是如果没想到或者根本不知道异或就无法好好解题了. 代码: int singleNumber(vector<int>& nums…

Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. For example: Given nums = [1, 2, 1, 3, 2, 5], return [3, 5]. Note: The order…

Given an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 这道题是之前那道 Single Number 单独的数字的延伸,那道题的解法…

Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 本来是一道非常简单的题,但是由于加上了时间复杂度必须是O(n),并且空间复杂度为O(1)…

[1]LeetCode 136 Single Number 题意:奇数个数,其中除了一个数只出现一次外,其他数都是成对出现,比如1,2,2,3,3...,求出该单个数. 解法:容易想到异或的性质,两个相同的数异或为0,那么把这串数从头到尾异或起来,最后的数就是要求的那个数. 代码如下: class Solution { public: int singleNumber(vector<int>& nums) { ; ;i<nums.size();i++) sum ^= nums[i…

问题: Given an array of integers, every element appears three times except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?   Single Number I 升级版,一个数组中其它数出现了…

Given 2*n + 1 numbers, every numbers occurs twice except one, find it. Have you met this question in a real interview? Yes Example Given [1,2,2,1,3,4,3], return 4 Challenge One-pass, constant extra space. LeetCode上的原题,请参见我之前的博客Single Number. class So…

Single Number I : Given an array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? Solution: 解法不少,贴一种: class…

Given an array of integers, every element appears twice except for one. Find that single one. 思路: 最经典的方法,利用两个相同的数异或结果为0的性质,则将整个数组进行异或,相同的数俩俩异或,最后得到的就是那个single number,复杂度是O(n) 代码: class Solution { public: int singleNumber(vector<int>& nums) { int…

最近做的题记录下. 258. Add Digits Given a non-negative integer num, repeatedly add all its digits until the result has only one digit. For example: Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it. int addDigi…

Given an array of integers, every element appears twice except for one. Find that single one. 本题利用XOR的特性, X^0 = X, X^X = 0, 并且XOR满足交换律. class Solution(object): def singleNumber(self, nums): """ :type nums: List[int] :rtype: int ""…

题目: Given an array of integers, every element appears three times except for one. Find that single one. Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?…

题目描述: Single Number Given an array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? Single Number II Given…

Single Number: 1. Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 代码: class Solution { publi…

感谢:http://www.cnblogs.com/changchengxiao/p/3413294.html Single Number Total Accepted: 103007 Total Submissions: 217483 Difficulty: Medium Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorith…

一:Number of 1 Bits 题目: Write a function that takes an unsigned integer and returns the number of '1' bits it has (also known as the Hamming weight). For example, the 32-bit integer '11' has binary representation 00000000000000000000000000001011, so t…

题目地址:here 题目大意:一个整数数组中,只有一个数出现一次,其余数都出现3次,在O(n)时间,O(1)空间内找到这个出现一次的数 对于”只有一个数出现一次,其余数出现2次“的情况,很简单,只要把数组中所有数异或的结果就是这个出现一次的数,leetcode上也有这个题目. 关于本题:我们用一个大小为32的数组cnt来记录:(int数据的每个二进制位1的出现次数)%3,程序中cnt[i]记录第i+1个二进制位.如果某个数出现了三次并且他的第i个二进制位为1,因为做了模3操作,那么该数对数组cn…

Given an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 没辙,智商碾压题.楼主没遇到之前就只会这种做法. public int si…

原题链接在这里:https://leetcode.com/problems/single-number-iii/ 题目: Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. For example: Giv…

Problem link: http://oj.leetcode.com/problems/single-number-ii/ The problem seems like the Single Number. Suppose we have following (3m+1) numbers in the array A: x0, x1, x1, x1, ..., xm, xm, xm We are asked to find out the value of x0. However we ca…

Prolbem link: http://oj.leetcode.com/problems/single-number/ This prolbem can be solved by using XOR(exclusive OR) operation. Let x, y, and z be any numbers, and XOR has following properties: x XOR 0 is itself, i.e. x XOR 0 = 0; x XOR x is 0, i.e. x…

Given an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 思路: 这个题是Single Number的进阶版,如果其他的数都出现两次而…

Problem Discription: Suppose the array A has n items in which all of the numbers apear 3 times except one. Find the single number. int singleNumber2(int A[], int n) { ; while(n--) { ret ^= A[n]; } return ret; } Related Problem: Suppose the array A ha…

I title: Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 思路:异或 class Solution { public: int…

Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. For example: Given nums = [1, 2, 1, 3, 2, 5], return [3, 5]. Note: The order…

Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 看到这种题第一个想法就是hashset啊哈哈哈. 根据hashset的特性,如果hash…

Problem 1:一个数组中有一个数字a只出现一次,其他数字都出现了两次.请找出这个只出现一次的数字? 考察知识点:异或运算 思路:比如数字 b^b = 0     a^0 = a 因此,可以将数组中的所有数字进行异或,而最终异或的结果即为所求只出现一次的数字a. 代码: def SingleNumber1(Array): ret = 0 for i in Array: ret ^= i return ret ==========================================…