DATA STRUCTURE CODES-II

PROGRAM TO FIND STRING LENGTH

#include<stdio.h>
main()
{
char str1[10];
char *p;
int i=0;
printf("enter the string to be read \n");
gets(str1);
p=str1;
while((*p)!='\0')
{
i++;
*p++;
}
printf("the length of the string is %d\n",i);
}

PROGRAM TO REVERSE A STRING

#include<stdio.h>
#include<string.h>
void rev(char *s1,char *s2);
main()
{
char s1[10],s2[10];
printf("enter a string \n");
gets(s1);
rev(s1,s2);
printf("reverse string =%s\n",s2);
}

void rev(char *s1,char *s2)
{
int i,j,len;
for(i=0;*(s1+i)!='\0';i++)
;
len=i;
for(j=0;j<len;j++){
*(s2+j)=*(s1+i-1);
--i;
}
*(s2+j)='\0';

}

PROGRAM TO COPY A STRING

#include<stdio.h>

main()

{

char str1[10],str2[10];

char *p,*q;

printf("enter the string str1 to be read \n");

gets(str1);

p=str1;

q=str2;

while((*p)!='\0')

{

*q=*p;

*p++;

*q++;

}

*q='\0';

printf("the copied string in str2 is: %s\n",str2);

}

PROGRAM TO COMPARE TO STRINGS

#include<stdio.h>

#define size 50

int str_comp(char *p,char *q);

main()

{

char s1[size],s2[size];

int flag;

printf("enter the first string to be read\n");

scanf("%s",&s1);

printf("enter the second string to be read\n");

scanf("%s",&s2);

flag=str_comp(s1,s2);

if(flag==0){

printf("not equal\n");

}

else{

printf("equal\n");

}

}

int str_comp(char *p,char *q)

{

int i,flag=1;

for(i=0;*(p+i)!='\0'&&*(q+i)!='\0';i++)

{

if(*(p+i)!=*(q+i)){

flag=0;

break;

}

}

if(*(p+i)=='\0'&& *(q+i)=='\0'&& flag==1)

{

return(1);

}

return(0);

}

PROGRAM TO CONCATENATE TWO STRINGS

#include<stdio.h>

main()

{

char str1[20],str2[20],str3[20];

char *p,*q,*r;

printf("enter the first string to be read\n");

gets(str1);

printf("enter the second string to be read\n");

gets(str2);

p=str1;

q=str2;

r=str3;

while((*p)!='\0')

{

*r=*p;

*p++;

*r++;

}

while((*q)!='\0')

{

*r=*q;

*q++;

*r++;

}

*r='\0';

printf("the concatinated string is :%s\n",str3);

}

PROGRAM TO PERFORM QUEUE OPERATION 

#include<stdio.h>    //preprossecor directives

# define size 3      // queue size

int ite,front=0,rear=-1,q[size];       

void insertq()       

{

if(rear==size-1)      

{

printf("************************queuoverflow**********************\n");

return ;

}

else

rear=rear+1;

q[rear]=ite;

}

 int deleteq()    

{

if(front>rear)

return-1;

return q[front++];

}

void display()    

{

int i;

if(front>rear)    

{

printf("*****************queue is empty****************\n");

return ;

}

printf("contents of the queue\n");

for(i=front;i<=rear;i++)

{

printf("%d\n",q[i]);

}

}

void main()    

{

int choice;   

for(;;)

{

printf("1:INSERT\n");

printf("2:DELETE\n");

printf("3:DISPLAY\n");

printf("4:EXIT\n");

printf("enter the choice \n");

scanf("%d",& choice);

switch(choice)

{

case 1:

printf("enter the item to be inserted \n");  

scanf("%d",&ite);

insertq();  

break;

case 2:

ite=deleteq();

if(ite==-1){

printf("***************queue empty**************** \n");}

else

printf("item delete a=%d \n",ite);

break;

case 3 :

display();

break;

default :

exit(0);

}

}

}