Implementation of string size comparison function

Now C + + has supported direct comparisons between strings.

But the previous time encountered a pen question, let oneself implement the function to complete the comparison between two strings.

As we all know, the comparison process is very simple, is a character-by-letter comparison of the size of the ASCII code value. But it was a little bit of a hassle when it came true personally.

The code is as follows for Yimeimei reference

Exp2.cpp: Defines the entry point of the console application.
//

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
int Scompare (string s1,string s2);
int main ()
{
	
	cout<< "enter S11" <<endl;
	string S11,s22;
	Getline (CIN,S11);
	cout<< "Enter S22" <<endl;
	Getline (CIN,S22);
	Switch (Scompare (S11,S22)) {case
	0:cout<< "S1>s2" <<endl;break;
	Case 1:	cout<< "S1<s2" <<endl;break;
	Case 2:cout<< "S1=s2" <<endl;
	}
	return 0;
}
int Scompare (const string S1,const string s2) {
int i=0;
while (s1[i]!= ' &&s2[i]!= ') {
	if (S1[i]>s2[i])
		return 0;
	 if (S1[i]<s2[i])
		return 1;
	if (S1[i]==s2[i])
		i++;
}
if (s1[i]!= ')
	return 0;
if (s2[i]!= ')
	return 1;
if (s1[i]== ' &&s2[i]== ')
	return 2;
}

The biggest trouble with this process is that in the process of writing the Scompare function, the formal parameter is not defined as a const type, resulting in a always-crossed error.