d_instruction.h

后辍表达式的计算

#include<iostream>
using namespace std;
class instruction{
public:
	instruction();//默认的构造函数
	instruction(char c);//引入算术符初始化对象
	char getCommand() const;//返回算术符
	friend bool operator>=(const instruction& left,const instruction& right);//如果left的出栈优先级>=right的的入栈优先级，返回true
private:
	char command;//算术符
	int inPriority;//入栈优先级
	int outPriority;//出栈优先级
};