Compare two string in C by R4R Team

Here we compare two string that they are equal or not.

program-

#include< stdio.h>
int main()
{
char ch1[20],ch2[20];
int i=0;
//input of string
printf("Enter first string\n");
scanf("%s",&ch1);
printf("Enter second string\n");
scanf("%s",&ch2);
while(ch1[i]!='' || ch2[i]!='')
{
if(ch1[i]!=ch2[i])
{
printf("Not same");
i=-1;
break;
}
i++;
}
if(i!=-1)
printf("Same");
}

Enter first string
Mystring
Enter second string
Mystring
Same

Enter first string
Mystring
Enter second string
My
Not same