Click on the links above
Exercise 1
Write a structure to represent an element of the form a+sqrt(-2)b for integer values a and b. Write a C function that takes two such complex numbers and returns the product of these numbers in the same form.
Solution 1
typedef struct {
int a;
int b;
} comp2;
comp2 mul ( comp2 z1 , comp2 z2 )
{
comp2 z;
z.a = (z1.a)*(z2.a) - 2*(z1.b)*(z2.b);
z.b = (z1.a)*(z2.b) + (z1.b)*(z2.a);
return z;
}
Exercise 2
Consider the following type definitions.
typedef struct {
char name[80];
char rollno[8];
float cgpa;
} stud1;
typedef struct {
char *name;
char *rollno;
float cgpa;
} stud2;
typedef stud1 *stud1ptr;
typedef stud2 *stud2ptr;
typedef stud1 stud1arr[100];
typedef stud2 stud2arr[100];
Assume that a pointer is of size 32 bits. Determine the following sizes:
sizeof(stud1) sizeof(stud2) sizeof(stud1ptr) sizeof(stud2ptr) sizeof(stud1arr) sizeof(stud2arr)
Solution 2
sizeof(stud1) = 80 + 8 + 4 = 92 sizeof(stud2) = 4 + 4 + 4 = 12 sizeof(stud1ptr) = 4 sizeof(stud2ptr) = 4 sizeof(stud1arr) = 92 x 100 = 9200 sizeof(stud2arr) = 12 x 100 = 1200
Exercise 3
Write a C function that accepts a non-empty array of complex numbers and returns the array element having the maximum magnitude.
Solution 3
typedef struct {
double re;
double im;
} complex;
complex maxmag ( complex A[] , int n )
{
int i, maxidx;
double t, max;
max = A[0].re * A[0].re + A[0].im * A[0].im;
maxidx = 0;
for (i = 1; i < n; ++i) {
t = A[i].re * A[i].re + A[i].im * A[i].im;
if (t > max) {
max = t;
maxidx = i;
}
}
return A[maxidx];
}
Exercise 4
What does the following program print? (Assume that an int is of size 32 bits.)
#include <stdio.h>
#include <stdlib.h>
#define MAXDIM 100
typedef int arr1[MAXDIM];
typedef struct {
int data[MAXDIM];
} arr2;
void f1 ( arr1 A )
{
A[0] = 12345;
}
void f2 ( arr2 A )
{
A.data[0] = 12345;
}
int main ()
{
arr1 A1;
arr2 A2;
printf("sizeof(A1) = %d\n", sizeof(A1));
printf("sizeof(A2) = %d\n", sizeof(A2));
A1[0] = 0; f1(A1); printf("A1[0] = %d\n", A1[0]);
A2.data[0] = 0; f2(A2); printf("A2.data[0] = %d\n", A2.data[0]);
exit(0);
}
Solution 4
sizeof(A1) = 400 sizeof(A2) = 400 A1[0] = 12345 A2.data[0] = 0
Exercise 5
Suppose that we want to represent lists of the following form:
(a (b (c) (d e f)) (g h))
The first item of the list is the character a, whereas its second item is again a list (b (c) (d e f)), and the third item (g h) is a list too. The following figure depicts a possible representation of such list.
Define a suitable data type to represent such lists.
Write a function to print such a list with properly nested parentheses.
Solution 5
typedef struct _node {
int type; /* zero for character, nonzero for (sub)list */
union { /* List item is a union of */
char data; /* either a character */
struct _node *sublist; /* or a sublist */
} item;
struct _node *next; /* pointer to the next item */
} node;
typedef node *list;
void prnlist ( list L )
{
node *p;
printf("(");
p = L;
while (p != NULL) {
if (p -> type == 0) printf("%c", (p->item).data);
else prnlist((p->item).sublist);
p = p -> next;
if (p != NULL) printf(" ");
}
printf(")");
}