题意: 给一个数组,其中仅有两个元素是出现1次的,且其他元素均出现2次.求这两个特殊的元素? 思路: 跟查找单个特殊的那道题是差不多的,只是这次出现了两个特殊的.将数组扫一遍求全部元素的异或和 x,结果也就是这两个特殊的元素的异或和了.现在必须找到两个当中的一个,才能恢复出另外一个.注意到x的二进制位中必定有1,那么只需要找到其中任意一个1对应的整数,再将数组中所有该位为1的计算他们的异或和a,a就是结果了,而另一个数b=x^a. vector<int> singleNumber(vector…

传送门 Description 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].…

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…

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…

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…

题意:判断一个字符串是否是一个合法的数字,包括正负浮点数和整形. 思路:有限自动机可以做,画个图再写程序就可以解决啦,只是实现起来代码的长短而已. 下面取巧来解决,分情况讨论: (1)整数 (2)浮点数 (3)整数e整数 (4)浮点数e整数 只有以上4种情况.但是要数之前可能带1个符号,这个可以直接过滤1个,而不影响结果.而且,其包含关系是从上到下扩展的,(1)扩展到(2),(3)扩展到 (4). 那么先解决符号 e 之前的,必须满足:正负号至多1个,有数字1个以上,点至多1个. 如果没有e,那…

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…

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…

传送门 Description Given an array of integers, every element appears three times except for one, which appears exactly once. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra me…

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…