two strings is given through the keyboard and fid which one is greater , smaller, or equal and also find their difference 2nd method. ( string )

#include<stdio.h>
#include<conio.h>
#include<string.h>
main()
{
    char str1[20],str2[20];
    int i=0,flag=0, x=0;

    printf("enter the first string :");
    gets(str1);

    printf("enter the second string :");
    gets(str2);

    while (str1[i] != '\0' && str2[i] != '\0')
    {
        x = str1[i]-str2[i];
        if(str1[i] != str2[i])
       { 
           flag=1;
           break;
       }
    
     
       else
       i++;
       
    }

    if (flag==0 && str1[i]=='\0' && str2[i]=='\0')
    printf("\n two string are equal and their difference is %d ",x);

    else 
    printf("\n two strings are not aqual and their difference is %d",x);

}   

output :

enter the first string :R
enter the second string :r

 two strings are not aqual and their difference is -32