为何后五个点RE

#include<iostream>
#include<cstring>
#include<stack>
#include<cstdio>
using namespace std;

string a;
stack<int> q;
int used=0;
char zf[10]={'0','1','2','3','4','5','6','7','8','9'};
int zf1[10]={0,1,2,3,4,5,6,7,8,9};
int tot;

int zh(char h)
{
    for(int i=0;i<9;i++)
    {
        if(h==zf[i])
        return zf1[i];
    }
}

int main()
{
    cin>>a;
    for(int i=0;i<a.size();i++)
    {
        if(a[i]=='.')
        {
            if(used==0)
            continue;
            q.push(used);
            used=0;
            continue;
        }
        used=zh(a[i]);
        if(a[i]=='+')
        {
            int b=q.top();q.pop();
            int c=q.top();q.pop();
            q.push(b+c);
            continue;
        }
        if(a[i]=='-')
        {
            int b=q.top();q.pop();
            int c=q.top();q.pop();
            q.push(c-b);
            continue;
        }
        if(a[i]=='*')
        {
            int b=q.top();q.pop();
            int c=q.top();q.pop();
            q.push(b*c);
            continue;
        }
        if(a[i]=='/')
        {
            int b=q.top();q.pop();
            int c=q.top();q.pop();
            q.push(c/b);
            continue;
        }
    }
    tot=q.top();
    printf("%d\n",tot);
    return 0;
}