shen_zhu的博客

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers su...

Given an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution, and you may not use the same el...

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.Example:Given a = 1 and b = 2, return 3.实现两个数相加而不用加减运算，可以分三步来执行。1，两个数相加而不去管进位，同二进制的抑或（^）运算。   2，将前一步产生的进位...

Given a 32-bit signed integer, reverse digits of an integer.Example 1:Input: 123Output: 321Example 2:Input: -123Output: -321Example 3:Input: 120Output: 21Note:Assume we are dealing with an envi...

Given a sequence of n integers a1, a2, ..., an, a 132 pattern is a subsequence ai, aj, ak suchthat i < j < k and ai < ak < aj. Design an algorithm that takes a list of n numbers as input a...

We have two special characters. The first character can be represented by one bit 0. The second character can be represented by two bits (10 or 11). Now given a string represented by several bits. Re...

Given an integer, write a function to determine if it is a power of two.方法一：bool isPowerOfTwo(int n) { if(n<0) return false; double s=log10(n)/log10(2); if(s-(int)s==0) ...

Given an integer, write a function to determine if it is a power of three. Follow up: Could you do it without using any loop / recursion?bool isPowerOfThree(int n) { if(n<=0) ...

Given two arrays, write a function to compute their intersection.Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2].Note:Each element in the result must be unique.The result can be in any ...

Given an array and a value, remove all instances of that value in-place and return the new length.Do not allocate extra space for another array, you must do this by modifying the input array in-place ...

Given an array of integers nums, write a method that returns the "pivot" index of this array.We define the pivot index as the index where the sum of the numbers to the left of the index is equal to th...

Rotate an array of n elements to the right by k steps.For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4]. void rotate(int* nums, int numsSize, int k) { int ...

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.Example 1Input: [3,0,1]Output: 2Example 2Input: [9,6,4,2,3,5,7,0,1]Output: 8Not...

You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1's elements in the corresponding places of nums2. T...

Given a circular array (the next element of the last element is the first element of the array), print the Next Greater Number for every element. The Next Greater Number of a number x is the first gre...

Write a function that takes a string as input and returns the string reversed.Example:Given s = "hello", return "olleh".方法：将前后的两个元素依次对调。          i=0,j=n-1;  i=1,j=n-2;  -->j=n-i-1          p=N/2-1...

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an integer n, write a function that returns true when it is a perfect...

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 mem...

Given a non-negative integer c, your task is to decide whether there're two integers a and b such that a2 + b2 = c.Example 1:Input: 5Output: TrueExplanation: 1 * 1 + 2 * 2 = 5Example 2:Input: 3Out...

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicates in the array.Exam...