class Solution { public: int singleNumber(int A[], int n) { int i,j; ; i<n; i++) { ; j<n; j++) { if(A[j]==A[i]) { ]; A[i+] = A[j]; A[j] = temp; i++; break; } } if(j==n) return A[i]; } } }; 上面的是传统方法,时间复杂度是O(n2),空间复杂度是O(1). class Solution { public: in…

class Solution { public: int singleNumber(int A[], int n) { ; ; ; i<=bits; i++) { ; ; ; j<n; j++) w += (A[j]>>(i-))&t; result+= (w%)<<(i-); //若是除过一个数之外,其他数重复k次,则将此处的3改为k } return result; } }; 利用二进制的位运算来解决这个问题,比如输入的数组是[2,2,3,2] 它们对应的二…

题目 Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array nums = [1,1,1,2,2,3], Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doe…

Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in the array. 这个和前面的一个不一样就在于可能会有重复的数字,那么判断的时候就应该注意了,遇到start…

题目链接:https://leetcode.com/problems/happy-number/ 题目理解:实现isHappy函数,判断一个正整数是否为happy数 happy数:计算要判断的数的每一位的平方和,平方和为1则为happy数,不为1则将原数替换为此平方和,继续上述步骤,直到等于1(为happy数),或者进入不包含1的无限循环(非happy数). 测试用例:19为happy数: 解题思路: 定义set集合存每次计算得到的需判断数n,循环计算新的原数n,终止条件为n等于1或者set中出…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. For example,Given input array nums …

题目:Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. For example,Given input array A…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

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 lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…