若只如初见

问题描述

Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher’s h-index.

According to the definition of h-index on Wikipedia: “A scientist has index h if h of his/her N papers have at least h citations each, and the other N − h papers have no more than h citations each.”

问题描述

Given an integer rowIndex, return the rowIndexth row of the Pascal’s triangle.

Notice that the row index starts from 0.

问题描述

Given a non-negative integer numRows, generate the first numRows of Pascal’s triangle.

前言

本文内容：

• 理解window对象——BOM的核心
• 控制窗口、框架和弹出窗口
• 利用location对象中的页面信息
• 使用navigator对象了解浏览器
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问题描述

There are N gas stations along a circular route, where the amount of gas at station i is gas[i].

You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank at one of the gas stations.

Return the starting gas station’s index if you can travel around the circuit once in the clockwise direction, otherwise return -1.

问题描述

You are playing the Bulls and Cows game with your friend.

You write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:

The number of “bulls”, which are digits in the guess that are in the correct position.

问题描述

Given an array, rotate the array to the right by k steps, where k is non-negative.

Follow up:

Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
Could you do it in-place with O(1) extra space?

本文内容

• 对象属性
• 创建对象
• 继承

面向对象的语言有一个标志，那就是他们都有类的概念，而通过类可以创建任意多个具有相同属性和方法的对象，但是ECMAScript中，没有类的概念。

可以把ECMAScript的对象想像成散列表。

每个对象都是基于一个引用类型创建的，这个引用类型可以是第5章讨论的原生类型，也可以是开发人员定义的类型。

前言

本章内容：

• 函数表达式的特征
• 使用函数实现递归
• 使用闭包定义私有变量
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问题描述

Given a sorted array nums, remove the duplicates in-place such that duplicates appeared at most twice and return the new length.

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

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Example 1:

Given nums = [1,1,1,2,2,3],

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3 respectively.

It doesn't matter what you leave beyond the returned length.