小强刷题~

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

Given an array of integers that is already sorted in ascending order, find two numbers such that the

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

Given a linked list, determine if it has a cycle in it. To represent a cycle in the given linked lis

Given a non-empty array of integers, every element appears twice except for one. Find that single on

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignori

Say you have an array prices for which the ith element is the price of a given stock on day i. Desig

Say you have an array for which the ith element is the price of a given stock on day i. If you were

Given a non-negative index k where k ≤ 33, return the kth index row of the Pascal's triangle. Note t

Given a non-negative integer numRows, generate the first numRows of Pascal's triangle. In Pascal's t

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all

Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shor

Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.For

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the long

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).

Given two binary trees, write a function to check if they are the same or not. Two binary trees are

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

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