Learn From The Masters

题目：The Hamming distance between two integers is the number of positions at which the corresponding bits are different.Given two integers x and y, calculate the Hamming distance.Note:

题目： Given two strings s and t which consist of only lowercase letters. String t is generated by random shuffling string s and then add one more letter at a random position. Find the letter that was

题目描述： 写一个函数，求两个整数之和，要求在函数体内不得使用+、-、*、/四则运算符号。思路： 首先看十进制是如何做的： 5+7=12，三步走 第一步：相加各位的值，不算进位，得到2。 第二步：计算进位值，得到10. 如果这一步的进位值为0，那么第一步得到的值就是最终结果。第三步：重复上述两步，只是相加的值变成上述两步的得到的结果2和10，得到12。同样我们可以用三步走的方式计算二进制值相

题目： 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 nums = [0, 1, 3] return 2.Note: Your algorithm should run in

题目： Given an integer, write a function to determine if it is a power of two.思路： 判断一个数是否是2的幂 2的N次幂的特点：仅有首位为1，其余各位都为0 代码：class Solution {public: bool isPowerOfTwo(int n) { return (n>0)

题目：Given an array of integers, every eleme：nt appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without u

题目：Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.You may assume that the array is non-empty and the majority

题目描述： 我们可以用2*1的小矩形横着或者竖着去覆盖更大的矩形。请问用n个2*1的小矩形无重叠地覆盖一个2*n的大矩形，总共有多少种方法？思路： 这题和前面的那道跳台阶是一模一样的题，也是动态规划，这里的2*1的小矩形横着放就是跳2阶，竖着放就是跳1阶，当大矩形长度小于等于2时，方法数量为长度本身；当大于2时，即为d[i]=d[i-1]+d[i-2],但是递归调用太耗时，就用迭代。代码：cla

题目： Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.Note: 1. The given integer is guaranteed to fit within the range o

题目： Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.思路： 其实就是模拟进位 1.首先最低位相加是要进一的 2.然后在做第二位的运算 3.以此类推，一直到没有进位为止。代码：class Solution {public: int get

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 0000000

题目： 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 and return them as an array.Example: For num = ...