第二组数据是这样的 10.28.30./*7.-@ 那么28/30得出来的应该是0呢还是个小数呢 代码：

include <iostream>

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
using namespace std;

struct stack {
    double s[100005];
    int _top;
    stack(double _top=0) {
        this->_top=_top;
    }
    void push(double x) {
        s[_top]=x;
        _top++;
    }
    void pop() {
        _top--;
    }
    double top() {
        return s[--_top];
    }
    bool empty() {
        return _top==0;
    }
    double size() {
        return _top;
    }
};//~~愉快的手写栈~~

string read() {
    string tmp;
    cin>>tmp;
    return tmp;
}

int main () {
    string n=read();
    double now=0;
    stack num;
    for (double i=0; n[i]!='@'; i++) {
        if (isdigit(n[i])) {
            now=now*10+(n[i]^48);
            continue;
        }
        if (n[i]=='.') {
            num.push(now);
            now=0;
            continue;
        }
        double ai=num.top(), bi=num.top(), ans;
        switch(n[i]) {
            case '+': {
                ans=ai+bi;
                num.push(ans);
                break;
            }
            case '-': {
                ans=bi-ai;
                num.push(ans);
                break;
            }
            case '*': {
                ans=bi*ai;
                num.push(ans);
                break;
            }
            case '/': {
                ans=bi/ai;
                num.push(ans);
                break;
            }
        }
    }
    printf("%.0lf", num.top());
    return 0;
}