#include "seqstack2.h"
#include "stdio.h"
#include <conio.h>


char ch;

int ExpEvaluation()/*讀入一個(gè)簡(jiǎn)單算術(shù)表達(dá)式并計(jì)算其值。operatsign和operatdata分別為運(yùn)算符棧和運(yùn)算數(shù)棧，OPS為運(yùn)算符集合*/
{
	char x,y;
	char op;
	int a,b,v;
	
	nStack operatdata;
	strStack operatsign;
	nInitStack(&operatdata);
	strInitStack(&operatsign);
	strPush(&operatsign,'#');
	
	printf("\nPlease input an expression (Ending with #) :\n");
    ch=getchar();

 	
 	strGetTop(&operatsign,&y);

 	while(ch!='#'||y!='#') /* strGetTop()通過(guò)函數(shù)值返回棧頂元素*/
   	{
		if(!In(ch))                   /*不是運(yùn)算符，是運(yùn)算數(shù)*/
		{
			
			int temp; 		   /*存放數(shù)字的臨時(shí)變量*/
			temp=ch-'0';
			/*將字符轉(zhuǎn)換為十進(jìn)制數(shù)*/
			fflush(stdin);
			ch=getchar();
			while(!In(ch))  //用ch逐個(gè)讀入運(yùn)算數(shù)的各位數(shù)碼，并轉(zhuǎn)化為十進(jìn)制數(shù)temp
			{
				temp=temp*10+ch-'0'; // 將逐個(gè)讀入運(yùn)算數(shù)的各位轉(zhuǎn)化為十進(jìn)制數(shù)
	 			fflush(stdin);
				ch=getchar();
			}  
   			nPush(&operatdata,temp);
		}
		else
      		switch(Compare(y,ch))
			{
	 			case '<': 
					strPush(&operatsign,ch); 
              		fflush(stdin);
					ch=getchar();
					break;
	 			case '=': 
					strPop(&operatsign,&x); 
					fflush(stdin);
					ch=getchar(); 
					break;
				case '>': 
					strPop(&operatsign,&op);
					nPop(&operatdata,&b);
					nPop(&operatdata,&a);
					v=Execute(a,op,b);  /* 對(duì)a和b進(jìn)行op運(yùn)算 */
					nPush(&operatdata,v);
					break;
			}
		strGetTop(&operatsign,&y);
	}
	nGetTop(&operatdata,&v);
	return (v);
}

void main()
{
	int result;   
    result=ExpEvaluation();
    printf("\n%d",result);
}