题解 | #挑7#

#include <iostream>
#include <string>
#include <set>

using namespace std;

int main ()
{
    int n;
    set<int> s;
    while(cin>>n)
    {
        for (int i=7;i<=n;i++)
        {
            if (i%7==0)
                s.insert(i);
            string  s1=to_string(i);
            if (s1.find('7')!=string::npos)
                s.insert(atoi(s1.c_str()));
        }
        cout<<s.size()<<endl;
        /*set<int>::iterator it;
         for (it=s.begin();it!=s.end();it++)
            cout<<*it<<" ";*/
        s.clear();
    }

}