Main idea LL(1) Parsing uses an explicit stack rather than recursive calls to perform a parse An example: – a simple grammar for the strings of balanced parentheses: S→(S) S∣ε The following table shows the actions of a top￾down parser given this grammar and the string ( )

Positional Number System Number system use positional notation to represent value. The position of the character(numeral) in a character string (collection of possible numerals) indicate value as well as the character itself. Radix (base) is the number of numeral characters in the character set of positional number system. Position Weiaht is a constant that represents the value of a position. Different position has different weight. It is the integer power of radix

Crofton's Method Let X1 and X2 be independent random variables that are uniformly distributed over the interval [o, a]. We are interested in computing E[ -X2l]. For instance, in an urban setting, X1 and X2 may denote the location of an accident and the location where an emergency vehicle is currently parked in a road segment of length a, respectively In this case, we want to know the distance

(ⅡI)形如 =fax+b+c a,x+b,+c 的方程, 其中a,a,b2,,2均为实常数

Unit Five Text B I. Pre-Reading Task 1.\Intel is the name of a(n A U.S. company B. IBM computer C government department D branch of the Internet 2. China is a country scientists and engineers in terms of computing technology

1. Intel 8255A是一个通用的可编程的并行接口芯片，内部有2个8位I/O口（A、B），两个4位I/O口（PC7～4、PC3～0）. 2. 通过编程可设置3种工作方式，可适用于CPU与I/O设备之间的多种数据传送方式的要求

化方阵A为Jordan标准形 特征向量法 1.在A的 Jordan矩阵中构 初等变换法

一、平面极坐标 设一质点在Oxy平面内运动,某时刻它位于点A.矢径与x轴之间的夹角为θ.于是质点在点A的位置可由A(r,)来确定以(r,0)为坐标的参考系为平面极坐标系

一、概率的定义 概率的公理化定义设E是随机试验,S是它的 样本空间,对于E的每一个事件A赋予一个实数P(A) 称之为事件A的概率,如果它满足下列三个条件:

#include #include void main() {int i,a,b,c; for(i=100;i<=999;i++) { a=i/100; /*求百分位*/ b=(i-100*a)/10; /*求十分位*/