shanshanhi的博客

Two Sum II - Input array is sorted 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 r

367. Valid Perfect SquareGiven a positive integer num, write a function which returns True if num is a perfect square else False.Note: Do not use any built-in library function such as sqrt.

35. Search Insert PositionGiven 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

34. Search for a RangeGiven an array of integers sorted in ascending order, find the starting and ending position of a given target value.Your algorithm's runtime complexity must be in the

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:Integers in each row are sorted from left to right.The first integer of

50. Pow(x, n)Implement pow(x, n).leetcode 上的top解法nest myPowdouble myPow(double x, int n) { if(n0) return 1/x * myPow(1/x, -(n+1)); if(n==0) return 1; if(n==2) return

4. Median of Two Sorted ArraysThere are two sorted arrays nums1 and nums2 of size m and n respectively.Find the median of the two sorted arrays. The overall run time complexity should be

209. Minimum Size Subarray SumGiven an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0

可采用hash、暴力、排序、映射、二分等多种方法。Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only...

222. Count Complete Tree NodesGiven a complete binary tree, count the number of nodes.Definition of a complete binary tree from Wikipedia:In a complete binary tree every level, except po

162. Find Peak ElementA peak element is an element that is greater than its neighbors.Given an input array where num[i] ≠ num[i+1], find a peak element and return its index.The array m

441. Arranging CoinsYou have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins.Given n, find the total number of full staircas

Is Subsequence Given a string s and a string t, check if s is subsequence of t. You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 5

Given a n x n matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix.Note that it is the kth smallest element in the sorted order, n

Given a binary search tree, write a function kthSmallest to find the kth smallest element in it.Note: You may assume k is always valid, 1 ≤ k ≤ BST's total elements.Follow up:What if the B

 Given four lists A, B, C, D of integer values, compute how many tuples (i, j, k, l) there are such that A[i] + B[j] + C[k] + D[l] is zero.To make problem a bit easier, all A, B, C, D have same length...

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).Find the minimum element.You may assume no duplicate exists in

Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed?Would this affect the run-time complexity? How and why?Suppose a sorted array is rotated at some piv

69. Sqrt(x)Implement int sqrt(int x).Compute and return the square root of x.此题同367题不同之处在于，此题徐哟求出sqrt(x)的值，而367题则不需要，367只用简单的判断是不是有个数的平方等于整数x方法一、二分查找法int mySqrt(int x) {        if(

33. Search in Rotated Sorted ArraySuppose an array sorted in ascending order 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

300. Longest Increasing SubsequenceGiven an unsorted array of integers, find the length of longest increasing subsequence.For example,Given [10, 9, 2, 5, 3, 7, 101, 18],The longest inc