These homeworks are not graded. However, we strongly encourage you to
do this and leave a copy in /afs/andrew/course/15/123/handin/homework/yourID

5.1 : The following code is supposed to swap two strings (char*'s)
      What can go wrong with the code? Assume A[i] and A[j] are strings
      with pre-allocated memory to hold strings s1 and s2. 

      char tmp[50];
      strcpy(tmp,A[i]);
      strcpy(A[i],A[j]);
      strcpy(A[j], tmp);


Ans: Need to assume that A[i] is less than 50 characters
     Need to assume that A[j] is less or equal to A[i]
     Need to assume A[j] has at least 50 bytes assigned to it  

5.2: What are some of the differences between char A[50] and char* A = malloc(50)?

ANS:  char A[50] allocates 50 stack bytes that can only be freed by compiler
      malloc(50) assigns 50 heap bytes that can be freed by programmer  

5.3: write your own strcpy function. 
     int mystrcpy(char* s1, char* s2){
         int n = strlen(s2),i;
         for (i=0; i<=n; i++)
             s1[i] = s2[i];
         
     }