I have designed the code perfectly but it is still not working

#1
#2 
#include<iostream>
#include<cstring>
using namespace std;
int string_to_int(string s,int n)
{
	//Base Case
	if(n==-1)
	{
		return 0;
	}
	int d=s[n]-'0';
	int sa=string_to_int(s,n-1);
	return (sa*10+d);
}
int main() {
	string s;
	cin>>s;
	int n=s.length();
	int ans=string_to_int(s,n-1);
    cout<<ans<<endl;
	return 0;
}

Just made a few changes please check.