编译原理词法分析四则运算C++程序
时间: 2024-06-19 10:02:43 浏览: 10
编译原理中,词法分析是将程序源代码分解成一系列单词(Token)的过程,常见的单词有关键字、标识符、操作符、常量和分隔符等。而四则运算是数学中常见的运算,包括加、减、乘、除四种运算。下面是一个简单的C++程序,实现了两个整数的四则运算:
```
#include <iostream>
using namespace std;
int main() {
int a = 10;
int b = 5;
int c, d, e, f;
c = a + b;
d = a - b;
e = a * b;
f = a / b;
cout << "a + b = " << c << endl;
cout << "a - b = " << d << endl;
cout << "a * b = " << e << endl;
cout << "a / b = " << f << endl;
return 0;
}
```
在词法分析的过程中,可以将该程序分解为以下单词序列:
```
[关键字] #include <iostream> using namespace std; [标识符] main ( ) { [关键字] int [标识符] a = [常量] 10 ; [关键字] int [标识符] b = [常量] 5 ; [关键字] int [标识符] c , [标识符] d , [标识符] e , [标识符] f ; [标识符] c = [标识符] a + [标识符] b ; [标识符] d = [标识符] a - [标识符] b ; [标识符] e = [标识符] a * [标识符] b ; [标识符] f = [标识符] a / [标识符] b ; [关键字] cout << "a + b = " << [标识符] c << endl ; [关键字] cout << "a - b = " << [标识符] d << endl ; [关键字] cout << "a * b = " << [标识符] e << endl ; [关键字] cout << "a / b = " << [标识符] f << endl ; return [常量] 0 ; }
```