James Pan

原题网址：https://leetcode.com/problems/missing-number/ Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. For example, Given n

原题网址：https://leetcode.com/problems/hamming-distance/ The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Given two integers x 

原题网址：https://leetcode.com/problems/gray-code/ The gray code is a binary numeral system where two successive values differ in only one bit. Given a non-negative integer n representing the total

原题网址：https://leetcode.com/problems/add-binary/ Given two binary strings, return their sum (also a binary string). For example, a = "11" b = "1" Return "100". 方法一：使用字符串来表示。 public class So

原题网址：https://leetcode.com/problems/n-queens-ii/ Follow up for N-Queens problem. Now, instead outputting board configurations, return the total number of distinct solutions. 方法一：深度优先搜索，使用一

原题网址：https://leetcode.com/problems/power-of-two/ Given an integer, write a function to determine if it is a power of two. 思路：数字n是2的整数次幂，当且仅当n的二进制表示有且只有一个1。 public class Solution { public boo

原题网址：342. Power of Four 342. Power of Four 342. Power of Four 342. Power of Four Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example: Given num =

原题网址：https://leetcode.com/problems/counting-bits/ Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation

原题网址：https://leetcode.com/problems/maximum-product-of-word-lengths/ Given a string array words, find the maximum value of length(word[i]) * length(word[j]) where the two words do not share comm

原题网址：https://leetcode.com/problems/range-sum-query-mutable/ Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. The update(i, val) function mo

原题网址：https://leetcode.com/problems/bitwise-and-of-numbers-range/ Given a range [m, n] where 0 For example, given the range [5, 7], you should return 4. 思路：总体思路就是求出m和n的高位比特的公共前缀。 方法一：变动前缀本身。

原题网址：https://leetcode.com/problems/number-of-1-bits/ 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

原题网址：https://leetcode.com/problems/reverse-bits/ Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100)

原题网址：https://leetcode.com/problems/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 runti

原题网址：https://leetcode.com/problems/single-number-ii/ Given an array of integers, every element appears three times except for one. Find that single one. Note: Your algorithm should have a lin

原题网址：https://leetcode.com/problems/single-number-iii/ Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the tw

原题网址：https://leetcode.com/problems/total-hamming-distance/ The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Now your job is