Exercise 7

Write a C program to insert a sub-string in to given main string from a given position.

SOURCE CODE:

/*Program to Inserting a Substring into Main String.*/

#include<stdio.h>

void main()

{

 char str[50],substr[20],temp[50];

 int i,j,pos,len=0;

 clrscr();

 printf("Enter string:\n");

 gets(str);

 printf("Enter substring:\n");

 gets(substr);

 printf("Enter the position where you want to insert:");

 scanf("%d",&pos);

 for(i=0;str[i]!='\0';i++)

  len++;

 if(pos>len)

  printf("\nInsertion is not possible.");

 else

 {

  for(i=pos,j=0;str[i]!='\0';i++,j++)

   temp[j]=str[i];

  temp[j]='\0';

  for(i=pos,j=0;substr[j]!='\0';i++,j++)

   str[i]=substr[j];

  for(j=0;temp[j]!='\0';j++,i++)

   str[i]=temp[j];

  str[i]='\0';

  printf("\nAfter Insertion the string is:\n");

  puts(str);

 }

}

OUTPUT:

Write a C program to delete n Characters from a given position in a given string.

SOURCE CODE:

/*Program to delete n characters from a given position in a given string.*/

#include<stdio.h>

#include<conio.h>

void main()

{

 char str[50],temp[50];

 int n,pos,i,j,len=0;

 clrscr();

 printf("\nEnter string:\n");

 gets(str);

 printf("\nEnter number of characters to delete:\n");

 scanf("%d",&n);

 printf("\nEnter postion where you want to delete:\n");

 scanf("%d",&pos);

 for(i=0;str[i]!='\0';i++)

  len++;

 if((pos+n)>len)

  printf("\nDeletion of characters not possible.");

 else

 {

  for(i=pos,j=pos+n;str[i]!='\0';i++,j++)

   str[i]=str[j];

  str[i]='\0';

  printf("\nAfter removing %d characters from %d position, string is:\n",n,pos);

  puts(str);

 }

}

OUTPUT:

Write a C program to replace a character of string either from beginning or ending or at a specified location.

SOURCE CODE:

/*Program to replace a character of string either from beginning or ending or at a specified location.*/

#include<stdio.h>

#include<conio.h>

void main()

{

 char str[50],ch;

 int opt,pos,i,len=0;

 clrscr();

 printf("\nEnter string:\n");

 gets(str);

 printf("\nEnter a character to replace:\n");

 ch=getche();

 for(i=0;str[i]!='\0';i++)

  len++;

 printf("\nMenu:\n1.Beginning\n2.Ending\n3.Specified Location\n");

 opt: printf("\nEnter option:\n");

 scanf("%d",&opt);

 switch(opt)

 {

  case 1:str[0]=ch;

break;

  case 2:str[len-1]=ch;

break;

  case 3:printf("\nEnter position:\n");

scanf("%d",&pos);

if(pos>len)

 printf("\nReplacing not possible.");

else

 str[pos]=ch;

break;

  default:printf("\nWrong option.");

 goto opt;

 }

 printf("\nAfter replacing character, String is:\n");

 puts(str);

}

OUTPUT: