rt，只有16分。#2,#4RE，#3,#5,#6WA

#include<bits/stdc++.h>
using namespace std;
int main()
{
	string a;
	int i=0,s1,s2,ans=0;
	stack<int> num; 
	cin>>a;
	while(1)
	{
		if(a[i]=='@')
		{
			cout<<num.top();
			return 0;
		}
		if(a[i]<58 && a[i]>47)
			num.push(int(a[i]-48));
		if(a[i]=='+')
		{
			s1=num.top();
			num.pop();
			s2=num.top();
			num.pop();
			ans=s1+s2;
			num.push(ans);
		}
		if(a[i]=='-')
		{
			s1=num.top();
			num.pop();
			s2=num.top();
			num.pop();
			ans=s2-s1;
			num.push(ans);
		}
		if(a[i]=='*')
		{
			s1=num.top();
			num.pop();
			s2=num.top();
			num.pop();
			ans=s2*s1;
			num.push(ans);
		}
		if(a[i]=='/')
		{
			s1=num.top();
			num.pop();
			s2=num.top();
			num.pop();
			ans=s2/s1;
			num.push(ans);
		}
		i++;
	}
	return 0;
}

测本地没有问题啊！