Remove Duplicates from Sorted Array IIDesicriptionFollow up for “Remove Duplicates”:What if dupli

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

Given a sorted linked list, delete all duplicates such that each element appear only once.

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 histogram.

Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing only 1’s and return its area.

x is guaranteed to be a non-negative integer.

filter 主要是做筛选用 filte括号里面结果满足返回true 不满足返回false，返回结果为return true筛选后的结果

Given two integers n and k, return all possible combinations of k numbers out of 1 … n.

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

The set [1,2,3,…,n] contains a total of n! unique permutations.