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…

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…

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…

原题地址:http://oj.leetcode.com/problems/single-number-ii/ 题意:Given an array of integers, every element appears three times except for one. Find that single one. 要求:和single number一样,线性时间复杂度,不能使用额外空间. 解题思路:这道题就比较难了.也是考察位操作.网上的位操作解法看了好半天也没有得其精髓.由于序列中除了那唯一的…

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? 题意:给定数组,除一个数仅出现一次外,其余都出现三次,找到仅出现一次的数字…

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? Hide Tags Bit Manipulation   数组中的数均出现3…

还记得<剑指offer>和<编程之美>等书上多次出现的找一个数组中仅仅出现一次的数那个题吗? leetcode也有这道题 链接here  相信大家都知道用异或在O(n)的时间复杂度内求出的方法,这里不再赘述. 以下就是上题的升级版 Given an array of integers, every element appears three times except for one. Find that single one. Note: Your algorithm should…

题目: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:一个比较好的方法是从位运算来考虑.每一位是0或1,由于除了一个数…

Description: Given an array of integers, every element appears three times except for one. Find that single one. 只有一个出现一次的数字,其他的都出现了3次,找出出现一次的那个数字. public class Solution { public int singleNumber(int[] nums) { Map<Integer, Integer> map = new HashMap…

题目描述: 给定一个包含n个整数的数组,除了一个数出现一次外所有的整数均出现三次,找出这个只出现一次的整数. 题目来源: http://oj.leetcode.com/problems/single-number-ii/ 题目分析: 对于除出现一次之外的所有的整数,其二进制表示中每一位1出现的次数是3的整数倍,将所有这些1清零,剩下的就是最终的数. 用ones记录到当前计算的变量为止,二进制1出现“1次”(mod 3 之后的 1)的数位.用twos记录到当前计算的变量为止,二进制1出现“2次”(…

题意:给一个序列,其中只有1个元素只出现1次,其他的都一定出现3次.问这个出现一次的元素是多少? 思路: (1)全部元素拆成二进制,那么每个位上的1的个数应该是3的倍数,如果不是3的倍数,则ans的这个位肯定为1. 22ms class Solution { public: int singleNumber(vector<int>& nums) { ]={}; ; i<nums.size(); i++) ; j<=; j++) &(nums[i]>>j)…

[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…

原题地址https://leetcode.com/problems/single-number-ii/ 题目描述Given an array of integers, every element appears three times except for one. Find that single one. 给出一个整数数组,除了某个元素外所有元素都出现三次.找出仅出现一次的数字. Note: 注意: Your algorithm should have a linear runtime co…

LeetCode 137. Single Number II(只出现一次的数字 II)…

题目 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? 分析 由上一题改动而来,LeetCode 136 Single Nu…

[LeetCode]137. Single Number II 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/single-number-ii/description/ 题目描述: Given an array of integers, every element appears three times except for one, which appears exactly once. Find that singl…

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…

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…

问题来源:Single Number II 问题描述:给定一个整数数组,除了一个整数出现一次之外,其余的每一个整数均出现三次,请找出这个出现一次的整数. 大家可能很熟悉另一个题目(Single Number):除了一个数出现一次之外,其余的均出现两次,找到出现一次的数.该问题很简单,大家肯定都知道解法:将所有的数异或,最后的结果即是出现一次的数.用到的知识是A^A=0,两个相同的数异或变为0,然后0^B=B,这样即可找到出现一次的数. 新问题有了变化,出现两次变成出现三次,整个问题的解法就不一样…

136. Single Number 除了一个数字,其他数字都出现了两遍. 用亦或解决,亦或的特点:1.相同的数结果为0,不同的数结果为1 2.与自己亦或为0,与0亦或为原来的数 class Solution { public: int singleNumber(vector<int>& nums) { if(nums.empty()) ; ; ;i < nums.size();i++) res ^= nums[i]; return res; } }; 137. Single N…

Single Number Given an array of integers, every element appears twice except for one. Find that single one. def singleNumber(self, A): l = len(A) if l < 2: return A[0] A.sort() for i in range(0,l-1,2): if A[i] != A[i+1]: return A[i] return A[l-1] 思路:…

Single Number II Given an array of integers, every element appears threetimes except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 解法一:开辟map记录次数 class So…

1. Sum Root to Leaf Numbers Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number. An example is the root-to-leaf path 1->2->3 which represents the number 123. Find the total sum of all root-to-leaf num…

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? 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)…

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…

LintCode 83. Single Number II (Medium) LeetCode 137. Single Number II (Medium) 以下算法的复杂度都是: 时间复杂度: O(n) 空间复杂度: O(1) 解法1. 32个计数器 最简单的思路是用32个计数器, 满3复位0. class Solution { public: int singleNumberII(vector<int> &A) { int cnt[32] = {0}; int res = 0; f…

题目描述: 给定一个数组,里面除了一个数字,其他的都出现三次.求出这个数字 原文描述: 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 m…

Single Number Total Accepted: 103745 Total Submissions: 218647 Difficulty: Medium 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 imp…

Single Number II Given 3*n + 1 numbers, every numbers occurs triple times except one, find it. Example Given [1,1,2,3,3,3,2,2,4,1] return 4 Challenge One-pass, constant extra space. 统计每一位上的1出现的次数,然后模3 , 题目上的3 * n + 1给了提示,然后又做过一题2 * n + 1的位操作. public…