What is wrong in my C code for a program about strcmp()?

Question

I am writing a program for comparing two strings without using strcmp(). But, am unable to get my desired result. Here is the code for my program.

#include<stdio.h>
int main(int argc, char const *argv[]) {
   int i,j;
   char a[90],b[90];
   printf("Enter the first string:");
   scanf("%s", &a[90]);
   printf("Enter the second string:");
   scanf("%s", &b[90]);
   for ( i = 0; a[i] != '\0' && b[i] != '\0'; i++) {
      if (a[i] == b[i]) {
         /* code */
         printf("Equal %d \n", a[i]-b[i]);
continue;
      } if (a[i] > b[i]) {
         /* code */
         printf("ai is big %d \n", a[i]-b[i]);
         break;
      }
      if (a[i] < b[i]) {
         /* code */
         printf("%d bi is the biggest \n", a[i]-b[i]);
         break;
      }

   }


   return 0;
}

When I execute the program in my terminal the compiler takes the input strings and then stops. I tried it a lot but am unable to figure it out. Can anyone help me out...!

Answer 1

The name of your first array is a, not a[90].

Similarly, the name of your second array is b, not b[90].

The expressions a[90] and b[90] name one element after the end of a and b.

So, by writing &a[90] and &b[90] you are instructing scanf to write just after each array, which is very bad and wrong.

You probably meant &a[0] and &b[0]?

However, scanf is very dangerous and you should not be using it at all.