pipiang的博客

 Two SumGiven 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...

70. Climbing StairsExample 2:Input: 3Output: 3Explanation: There are three ways to climb to the top.1. 1 step + 1 step + 1 step2. 1 step + 2 steps3. 2 steps + 1 step斐波那契数列方法一备忘录算法 int[] map = ne...

125. Valid PalindromeGiven a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.Note: For the purpose of this problem, we define empty string as valid...

66. Plus OneGiven a non-empty array of digits representing a non-negative integer, plus one to the integer.The digits are stored such that the most significant digit is at the head of the list, and ea...

121. Best Time to Buy and Sell StockSay you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (i.e., buy one...

53. Maximum SubarrayGiven an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.Example:Input: [-2,1,-3,4,-1,2,1,-5,4],Outp...

110. Balanced Binary TreeGiven a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as:a binary tree in which the depth of the two subtrees of e...

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 assume no du...

Given an array nums and a value val, 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 ...

101. Symmetric TreeGiven a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / ...

88. Merge Sorted ArrayGiven two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.Note:The number of elements initialized in nums1 and nums2 are m and n respectively.Yo...

 Merge Two Sorted ListsMerge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.Example:Input: 1->2->4, 1->...

2. Add Two NumbersYou are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two nu...