Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.…

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return …

Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 关于…

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path f…

Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +,&nb…

Given n non-negative integers representing an elevation map where the width of each bar is 1, comput…

Given an array S of n integers, are there elements a, b, c, and d …

Given a sorted array and a target value, return the index if the target is found. If not, return the index whe…

Given two numbers represented as strings, return multiplication of the numbers as a string. Note: The numbers …

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

Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number…

实现double Pow(double x,int n)—-x的n次幂！ 题目解析： 这道题目看起来很简单，笨方法，可以一次一次的去乘，也可以折半相乘！看似简单，但中间碰到了不小的问题。 在运行过程中，出现了…