sop.h

自己做的数据结构实验题（合并链表

#include"stack.h"


//define the precedence level of operation used as first operation
int First(char op){
	switch(op){
	case'+':
	case'-':
		return 3;
	case'*':
	case'/':
		return 5;
	case'(':
		return 1;
	case')':
		return 7;
	case'#':
		return 0;
	default: 
		return -1;
	}
}
//define the precedence level of operation used as second operation
int Second(char op){
	switch(op){
	case'+':
	case'-':
		return 2;
	case'*':
	case'/':
		return 4;
	case'(':
		return 8;
	case')':
		return 1;
	case'#':
		return 0;
	default: 
		return -1;
	}
}


//compare the precedence level of operation
int Precede(char firstop,char secondop){
	int a;
	a=First(firstop)-Second(secondop);
	return a;
}

//operate the expression

int Operate(int ca,char theta,int cb){
int a,b;
a=ca;
b=cb;
	switch(theta){
	case'+': 
		return (a+b);
	case'-':return (a-b);
	case'*':return (a*b);
	case'/':return (a/b);
	default: 
		return -1;
	}
}

bool In(char c){
return (35<=c&&c<=47);
}