James Pan

原题网址：https://leetcode.com/problems/contains-duplicate-iii/Given an array of integers, find out whether there are two distinct indices i and j in the array such that the difference between nums[i] 

原题网址：https://leetcode.com/problems/remove-duplicate-letters/Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You mus

原题网址：https://leetcode.com/problems/max-sum-of-sub-matrix-no-larger-than-k/Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is

红黑树的两种基本操作做旋转和右旋转，LEFT_ROTATE(x)和RIGHT_ROTATE(x)分别表示以x为支点进行左旋转和右旋转。红黑树的插入操作以插入点为当前点（z），检查是否满足红黑树规则，如果不满足则调整，直至完全满足为止。根据当前点z的父节点和叔叔节点的颜色，可以分为均为红色以及叔叔节点为黑色的情况，而根据当前节点是父节点的做节点还是右节点分为两种情况。