摘要： Given preorder and inorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. 思路还是比较简单的，在中 阅读全文

摘要： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may comple 阅读全文

摘要： Your are given an array of integers prices, for which the i th element is the price of a given stock on day i; and a non negative integer fee represen 阅读全文

摘要： Given a string containing just the characters and , find the length of the longest valid (well formed) parentheses substring. For , the longest valid 阅读全文

摘要： Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or 阅读全文

摘要： Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element 阅读全文

摘要： Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height balanced bina 阅读全文

摘要： Given a string, find the length of the longest substring without repeating characters. 思路：用map维护区间内各个字母的数量，然后遇到已经访问过的就进行滑动区间，来得到符合条件的区间，然后求最大区间长度。 虽然时 阅读全文

摘要： Given n non negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the hist 阅读全文

摘要： 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 r 阅读全文