#include <iostream>

using namespace std;

int main() {
int n,i,br;
cin>>n;
br=0;
while(n>0){
i=n%10;
n=n/10;
br=br+1;
}
cout<<br;
return 0;
}
}

2.nacin preko stringova

#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;

int main()
{
int br;
string rec;
cout<<„Unesi visecifren broj“<<endl;
cin>>rec;
cout<<„Broj cifara „<<rec.size()<<endl;
system(„PAUSE“);
return EXIT_SUCCESS;
}