How will you free the allocated memory ?

How will you free the allocated memory ?

2) What is the output of this C code(according to C99 standard)?

#include <stdio.h>
     struct p     {
         int k;
         char c;
         float f;
     };
     int main()
     {
         struct p x = {.c = 97, .f = 3, .k = 1};
         printf("%f\n", x.f);
     }

3) What is the output of this C code?

#include <stdio.h>
     struct student     {
         int no;
         char name[20];
     }
     void main()
     {
         struct student s;
         s.no = 8;
         printf("hello");
     }

4) What is the output of this C code?

#include <stdio.h>
     struct p     {
         int k;
         char c;
         float f;
     };
     int p = 10;
     int main()
     {
         struct p x = {1, 97};
         printf("%f %d\n", x.f, p);
     }

5) Can the below code be compiled successfully?

#include <stdio.h>
     struct p     {
         int k;
         char c;
         float f;
     };
     int main()
     {
         struct p x = {.c = 97, .f = 3, .k = 1};
         printf("%f\n", x.f);
     }