这是我的源代码

#include<bitsdc++.h>
typedef long long ll;
typedef double db;
#define F1(i,a,b) for( int i=(a); i<=(b); i++)
#define F2(i,a,b) for( int i=(a); i<(b); i++)
#define F3(i,a,b) for( int i=(a); i>=(b); i--)
#define F4(i,a,b) for( int i=(a); i>(b); i--)
using namespace std;
stack<int>coun;
int x,y,num,ans;
string s1;
int i,j;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	
	cin>>s1;
	while(s1[i]!='@')
	{
		if(s1[i]>='0'&&s1[i]<='9')
		{
			num=s1[i]-'0';
		}
		else if(s1[i]=='.')
		{
			coun.push(num);
		}
		else if(s1[i]!='@')
		{
			if(s1[i]=='+')
			{
				x=coun.top();  coun.pop();
				y=coun.top();  coun.pop();
				coun.push(y+x);
				continue;
			}
			else if(s1[i]=='-')
			{
				x=coun.top();  coun.pop();
				y=coun.top();  coun.pop();
				coun.push(y-x);
				continue;
			}
			else if(s1[i]=='*')
			{
				x=coun.top();  coun.pop();
				y=coun.top();  coun.pop();
				coun.push(x*y);
				continue;
			}
			else if(s1[i]=='/')
			{
				x=coun.top();  coun.pop();
				y=coun.top();  coun.pop();
				coun.push(y/x);
				continue;
			}
		}
		i++;
	}
	cout<<coun.top()<<endl;
	return 0;
}