Tutorial  8.1.a:

Check output of the following program.
void main ()
{
int a,*b,**c,***d,****e;
a=10;
b=&a;
c=&b;
d=&c;
e=&d;
printf(“\n a=%d b= %u c=%u d=%u e=%u”, a ,b, c, d, e);
printf(“\n a=%d a+*b= %d **c + ***d=%d ***d + ****e=%d ”,a,
a+*b, **c + ***d, ***d + ****e);
}
 

Tutorial 8.1.b:
Write a C program to swap two variables
void main()
{
int a=5,b=10;
printf(“Before Swap:\n a=%d and b=%d”,a,b);
swap(a,b);
printf(“After swap:\n a=%d and b=%d”,a,b);
swap_ptr(&a,&b);
printf(“After swap using pointer: \n a=%d and b=%d”,a,b);
}

void swap(int a, int b)
{
int temp;
temp=a;
a=b;
b=temp;
}

void swap_ptr(int *a, int *b)
{
int temp;
temp=*a;
*a=*b;
*b=temp;
}
 

Output: Before Swap:

Tutorial 8.1.c:
Write a C program to read a string of length N and copy it to another memory location using pointers and Dynamic memory allocation.
Soln:
#include<stdio.h>
#include<stdlib.h>

void strcopy(char *s,char *t)
{
while((*t++ = *s++) !='\0');
}

int main()
{
char *str1;
char *str2;
int len;

printf("Enter Length of the string: ");
scanf("%d",&len);

str1 = (char *)malloc(len*sizeof(char));
str2= (char *)malloc(len*sizeof(char));
printf("\nEnter the String: ");
scanf("%s",str1);
strcopy(str1,str2);
printf("\n Input String stored in str1=%s and copied to  str2=%s",str1,str2);
return 0;
}

Output: Enter Length of the string: 8

            Input String stored in str1=Pointers and copied to  str2=Pointers
 

Assignment 8.1:
Write a C program to read a string of length N (given as input) the string memory should be dynamically allocated and then write user defined functions performs the following string operations. You are not allowed to use any string library functions. Moreover array constructs like a[i] cannot be used.

a) strComp (char *S, char *T):  compares two strings S and T .
return <0 if S<T
return 0 if S==T
return >0 if S>T, Here " < " or " > " implies less or greater according to ASCII values.
 

Input                        Output

S= abc T= def            -1

OUTPUT: gabcdef     fgabcde     efgabcd     defgabc    cdefgab    bcdefga         abcdefg

d) strReverse (char *S): Function accepts an array of N strings of length K as input argument and return the reverse of each of the strings.
    I. Construct a 2-Dimensional array using dynamic memory allocation to store the given input strings.
    II. The input string are of different length.
    III. Your strReverse( ) function must be “In Place”.

Hint: You can modify the Swap( ) function as shown. You have to use just two variables to swap. in Tutorial 8.1.b.

For example:
Input        :      N = 5 K=4,4,3,7,3

Amit    Ajay    Mal    aravind    ram

Output    :  Reverse order of  given strings :

tima   yaja    lam   dnivara    mar