Stack expression

Preface

Stack ： Last in, first out

No description , First learn to look at the code , Code can run , Pay attention to the input format ,,

expression - Infix

#include<iostream>
using namespace std;

#define ERROR 0;
#define OK -1;
typedef int status;

typedef struct Stack{
    
	int data;
	struct Stack *next;
}Stack,*LinkList;

void instack(LinkList &S){
    
	S=new Stack;
	S=NULL;
}

status push(LinkList &S,char e){
    				// Into the stack  
	Stack *p;
	p=new Stack;
	p->data=e;
	p->next=S;
	S=p;
	return OK;
}


status pop(LinkList &S,char &e){
    			// Out of the stack  
	if(S==NULL) return ERROR;			// The stack is empty  
	Stack *p;
	p=S;
	e=S->data;
	S=S->next;
	delete p;
	return OK;
}

int gettop(LinkList S){
    	
	return S->data;
}

status In(char ch){
    
	switch(ch){
    
		case '0':
		case '1':
		case '2':
		case '3': 
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9': return OK;
		default :return ERROR;
	}
}

char operate(char first,char optr,char second){
    
	int a,b;
	a=first-'0';
	b=second-'0';
	switch(optr){
    
		case '+':
			return a+b+'0';
		case '-':
			return a-b+'0';
		case '*':
			return a*b+'0';
		case '/':
			return a/b+'0';
	}
}

char precede(char ch1,char ch2){
    
	if(ch1==ch2&&ch1!='#')
		return '>';
	switch(ch1){
    
		case '+':
		case '-':
			switch(ch2){
    
				case '*':
				case '/':return '<';
				default :return '>';
			}
		case '*':
		case '/':
			switch(ch2){
    
				case '(':return '<';
				default :return '>';
			}
		case '(':
			switch(ch2){
    
				case ')':return '=';
				case '#':return '!';
				default :return '<';
			}
		case ')':
			switch(ch2){
    
				case '(':return '!';
				default :return '>';
			}
		case '#':
			switch(ch2){
    
				case '#':return '=';
				case ')':return '!';
				default :return '<';
			}
		}
}

int Expression(){
    
	char a,b,oper;
	char ch;
	Stack *oped,*optr;
	instack(oped);			// Stack - Count  
	instack(optr);			// Stack - Operator  
	push(optr,'#');
	cin>>ch;
	while(ch!='#'||gettop(optr)!='#'){
    
		if(In(ch)){
    
			push(oped,ch);
			cin>>ch;}
		else{
    
			switch(precede(gettop(optr),ch)){
    
				case '<':
					push(optr,ch);
					cin>>ch;
					break;
				case '>':
					pop(optr,oper);
					pop(oped,b);pop(oped,a);
					push(oped,operate(a,oper,b));
					break;
				case '=':
					pop(optr,oper);
					cin>>ch;
					break;
				case '!':
					cout<<" The expression is wrong "<<endl;
					return 0;
			}
		}
	}
	return gettop(oped)-'0';
}



int main()
{
    
	int choose=-1;
	cout<<1<<"： Enter the expression "<<endl;
	cout<<0<<"： sign out "<<endl;
	while(choose!=0){
    
		cout<<" Enter the expression ："<<endl; 
		cout<<" value ："<<Expression()<<endl;
		cout<<" Please select ：";
		cin>>choose;
		cout<<endl;
	}
	return 0;
}

expression - suffix

#include<iostream>
using namespace std;

#define ERROR 0;
#define OK -1;
typedef int status;

typedef struct Stack{
    
	int data;
	struct Stack *next;
}Stack,*LinkList;

void Instack(LinkList &S){
    
	S=new Stack;
	S=NULL;
}

status push(LinkList &S,char e){
    				// Into the stack  
	Stack *p;
	p=new Stack;
	p->data=e;
	p->next=S;
	S=p;
	return OK;
}

status pop(LinkList &S,char &e){
    			// Out of the stack  
	if(S==NULL) return ERROR;			 
	Stack *p;
	p=S;
	e=S->data;
	S=S->next;
	delete p;
	return OK;
}

int gettop(LinkList S){
    	
	return S->data;
}

status In(char ch){
    
	switch(ch){
    
		case '0':
		case '1':
		case '2':
		case '3': 
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9': return OK;
		default :return ERROR;
	}
}

char operate(char first,char optr,char second){
    
	int a,b;
	a=first-'0';
	b=second-'0';
	switch(optr){
    
		case '+':
			return a+b+'0';
		case '-':
			return a-b+'0';
		case '*':
			return a*b+'0';
		case '/':
			return a/b+'0';
	}
}

int Expression(){
    
	char ch;
	char a,b;
	LinkList S;
	Instack(S);
	cin>>ch;
	while(ch!='#'){
    
		if(In(ch))
			push(S,ch);
		else{
    
			pop(S,b);pop(S,a);
			push(S,operate(a,ch,b));
			}
		cin>>ch;
		}
	return gettop(S)-'0';
}

int main(){
    
	int choose=-1;
	cout<<1<<"： Enter the expression "<<endl;
	cout<<0<<"： sign out "<<endl;
	while(choose!=0){
    
		cout<<" Enter the expression ："<<endl; 
		cout<<" value ："<<Expression()<<endl;
		cout<<" Please select ：";
		cin>>choose;
		cout<<endl;
	}
	return 0;
}