目录 1. Math 对象:数学对象,提供对数据的数学计算.如:获取绝对值.向上取整等.无构造函数,无法被初始化,只提供静态属性和方法. 2. Number 对象 :Js中提供数字的对象.包含整数.浮点数等等.并提供数字的类型转换.小数点截取等方法. 1. Math 对象 1.1 介绍 Math 对象,是数学对象,提供对数据的数学计算,如:获取绝对值.向上取整等.无构造函数,无法被初始化,只提供静态属性和方法. 1.2 构造函数 无 :Math 对象无构造函数,无法被初始化,只提供静态属性和方法…

题意:求f(n)=1/1+1/2+1/3+1/4-1/n   (1 ≤ n ≤ 108).,精确到10-8    (原题在文末) 知识点:      调和级数(即f(n))至今没有一个完全正确的公式,但欧拉给出过一个近似公式:(n很大时)       f(n)≈ln(n)+C+1/2*n       欧拉常数值:C≈0.57721566490153286060651209       c++ math库中,log即为ln. 题解: 公式:f(n)=ln(n)+C+1/(2*n); n很小时直接求…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Eclipse 无法找到 该 断点,原因是编译时,字节码改变了,导致eclipse无法读取对应的行了 1.ANT编译的class Eclipse不认,因为eclipse也会编译class.怎么让它们统一呢,就是在build.xml里的javac标签里加上一句debug="true",一切就OK了. 如:<javac ... debug="true"> 链接:http://blog.csdn.net/liu251/article/details/36391…

/*移除HTML5 input在type="number"时的上下小箭头*/ input::-webkit-outer-spin-button, input::-webkit-inner-spin-button{ -webkit-appearance: none; margin:; } input[type="number"]{-moz-appearance:textfield;}…

真机调试免费App ID出现的问题The maximum number of apps for free development profiles has been reached.免费应用程序调试最大限度苹果免费App ID只能运行2个应用程序,当调试第三个的时候就会报这个错误,必须把之前的应用程序删除,才能调试新的 解决办法:1.连接iPhone 打开Xcode->Window->Devices     2.接着出现这个界面   3.删除其中一个,不是本次运行的应用程序 4.接着会弹框  …

每一个实数都能用有理数去逼近到任意精确的程度,这就是有理数的稠密性.The rational points are dense on the number axis.…

There are a number of spherical balloons spread in two-dimensional space. For each balloon, provided input is the start and end coordinates of the horizontal diameter. Since it's horizontal, y-coordinates don't matter and hence the x-coordinates of s…

Given n points in the plane that are all pairwise distinct, a "boomerang" is a tuple of points (i, j, k) such that the distance between i and j equals the distance between i and k (the order of the tuple matters). Find the number of boomerangs.…

Count the number of segments in a string, where a segment is defined to be a contiguous sequence of non-space characters. Please note that the string does not contain any non-printable characters. Example: Input: "Hello, my name is John" Output:…