James Pan

原题网址:https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/ Given an array nums and a target value k, find the maximum length of a subarray that sums to k. If there isn't one, return 0

原题网址：https://leetcode.com/problems/arithmetic-slices-ii-subsequence/ A sequence of numbers is called arithmetic if it consists of at least three elements and if the difference between any two con

原题网址：https://leetcode.com/problems/132-pattern/ Given a sequence of n integers a1, a2, ..., an, a 132 pattern is a subsequence ai, aj, ak such that i j k and ai < ak j. Design an algori

原题网址：https://leetcode.com/problems/binary-tree-upside-down/ Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or em

原题网址：https://leetcode.com/problems/russian-doll-envelopes/ You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and on

原题网址：https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/ Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to

原题网址：https://leetcode.com/problems/longest-consecutive-sequence/ Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4,

原题网址：https://leetcode.com/problems/repeated-dna-sequences/ All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is someti

原题网址：https://leetcode.com/problems/pascals-triangle/ Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return [ [1], [1,1], [1,2,1],

原题网址：https://leetcode.com/problems/unique-substrings-in-wraparound-string/ Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this: