#include <stdio.h>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */


int cal(char a[]){
	int i=0,num=0,;
	int result=0;
	char token='0';
	
	while(a[i]!='\0'){
		if(a[i]>'9' || a[i]<'0'){
				token=a[i];
				i++;
				continue;
		}
		
		num=0;
		while(a[i]<='9' && a[i]>='0'){
			num=num*10+(a[i]-'0');
			i++;
		}
		
		switch(token){
			case '*':
				result*=num;
				break;
			case '/':
				result/=num;
				break;
			case '+':
				result+=num;
				break;
			case '-':
				result-=num;
				break;
				
			default:
				result=num;
		}
	}
	
	return result;
}

int main(int argc, char *argv[]) {
	int sum;
	char s[25];
	
	puts("請輸入字串：");
    gets(s);
    printf("輸出的字串為\n");
    printf("%s \n",s);
	sum=cal(s);
	printf("輸出結果\n");
	printf("%d",sum);
	
	return 0;
}