Updated 5-d-18.c and others

assignment-2/3-swap-bitwise.c

@@ -11,8 +11,8 @@ void main() {
 }
 
 
-// 1101 
-// 1011
+// 1101 = 13
+// 1011 = 11
 // ----
 // 0110 => not matching 
 

assignment-5/d/17.c

@@ -55,9 +55,9 @@ int main() {
         else {
             printf("Not a perfect number.\n");
         }
-
+        break;
     default:
-
+        printf("Enter a valid option.\n");
         break;
     }
     return 0;

assignment-5/d/18-prime_and_Automorphic.c

@@ -1,9 +1,9 @@
 /*
-Write a menu driven C program to accept a number from the user and check whether it is a Palindrome or a Perfect number.
-(a) Palindrome number: (A number is a Palindrome which when read in reverse order is same as in the right order)
-Example: 11, 101, 151 etc.
-(b) Perfect number: (A number is called Perfect if it is equal to the sum of its factors other than the number itself.)
-Example: 6 = 1 + 2 + 3
+Write a menu driven C program to accept a number from the user and check whether it is a Prime number or an Automorphic number.
+(a) Prime number: (A number is said to be prime, if it is only divisible by 1 and itself)
+Example: 3,5,7,11
+(b) Automorphic number: (Automorphic number is the number which is contained in the last digit(s) of its square.)
+Example: 25 is an Automorphic number as its square is 625 and 25 is present as the last two digits.
 */
 
 #include <stdio.h>
@@ -47,11 +47,14 @@ int main() {
         sq = num*num;
 
         while( sq/tens != 0){
+            // printf("sq = %d, tens = %d\t",sq,tens);
+            // printf("sq/tens = %d\t",sq/tens );
+            // printf("sq%%tens = %d\n",sq%tens);
             if (sq%tens == num){
                 automorphic = 1;
                 break;
             }
-            tens += 10;
+            tens *= 10;
         }
 
         if (automorphic){