Thorpedo
New member
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/*Operating and maintaining a list */
#include <stdio.h>
#include <stdlib.h>
/* self-referential structure */
struct listNode {
char data; /* define data as char */
struct listNode *nextPtr; /* listNode pointer */
}; /* end structure listNode */
typedef struct listNode ListNode;
typedef ListNode *ListNodePtr;
/* prototypes */
void insert( ListNodePtr *sPtr, char value );
char delete( ListNodePtr *sPtr, char value );
int isEmpty( ListNodePtr sPtr );
void printList( ListNodePtr currentPtr );
void instructions( void );
int main()
{
ListNodePtr startPtr = NULL; /* initialize startPtr */
int choice; /* user's choice */
char item; /* char entered by user */
instructions(); /* display the menu */
printf( "? " );
scanf( "%d", &choice );
/* loop while user does not choose 3 */
while ( choice != 3 ) {
switch ( choice ) {
case 1:
printf( "Enter a character: " );
scanf( "\n%c", &item );
insert( &startPtr, item );
printList( startPtr );
break;
case 2:
/* if list is not empty */
if ( !isEmpty( startPtr ) ) {
printf( "Enter character to be deleted: " );
scanf( "\n%c", &item );
/* if character is found */
if ( delete( &startPtr, item ) ) {
printf( "%c deleted.\n", item );
printList( startPtr );
} /* end if */
else {
printf( "%c not found.\n\n", item );
} /* end else */
} /* end if */
else {
printf( "List is empty.\n\n" );
} /* end else */
break;
default:
printf( "Invalid choice.\n\n" );
instructions();
break;
} /* end switch */
printf( "? " );
scanf( "%d", &choice );
} /* end while */
printf( "End of run.\n" );
return 0; /* indicates successful termination */
} /* end main */
/* display program instructions to user */
void instructions( void )
{
printf( "Enter your choice:\n"
" 1 to insert an element into the list.\n"
" 2 to delete an element from the list.\n"
" 3 to end.\n" );
} /* end function instructions */
/* Insert a new value into the list in sorted order */
void insert( ListNodePtr *sPtr, char value )
{
ListNodePtr newPtr; /* pointer to new node */
ListNodePtr previousPtr; /* pointer to previous node in list */
ListNodePtr currentPtr; /* pointer to current node in list */
newPtr = malloc( sizeof( ListNode ) );
if ( newPtr != NULL ) { /* is space available */
newPtr->data = value;
newPtr->nextPtr = NULL;
previousPtr = NULL;
currentPtr = *sPtr;
/* loop to find the correct location in the list */
while ( currentPtr != NULL && value > currentPtr->data ) {
previousPtr = currentPtr; /* walk to ... */
currentPtr = currentPtr->nextPtr; /* ... next node */
} /* end while */
/* insert newPtr at beginning of list */
if ( previousPtr == NULL ) {
newPtr->nextPtr = *sPtr;
*sPtr = newPtr;
} /* end if */
else { /* insert newPtr between previousPtr and currentPtr */
previousPtr->nextPtr = newPtr;
newPtr->nextPtr = currentPtr;
} /* end else */
} /* end if */
else {
printf( "%c not inserted. No memory available.\n", value );
} /* end else */
} /* end function insert */
/* Delete a list element */
char delete( ListNodePtr *sPtr, char value )
{
ListNodePtr previousPtr; /* pointer to previous node in list */
ListNodePtr currentPtr; /* pointer to current node in list */
ListNodePtr tempPtr; /* temporary node pointer */
/* delete first node */
if ( value == ( *sPtr )->data ) {
tempPtr = *sPtr;
*sPtr = ( *sPtr )->nextPtr; /* de-thread the node */
free( tempPtr ); /* free the de-threaded node */
return value;
} /* end if */
else {
previousPtr = *sPtr;
currentPtr = ( *sPtr )->nextPtr;
/* loop to find the correct location in the list */
while ( currentPtr != NULL && currentPtr->data != value ) {
previousPtr = currentPtr; /* walk to ... */
currentPtr = currentPtr->nextPtr; /* ... next node */
} /* end while */
/* delete node at currentPtr */
if ( currentPtr != NULL ) {
tempPtr = currentPtr;
previousPtr->nextPtr = currentPtr->nextPtr;
free( tempPtr );
return value;
} /* end if */
} /* end else */
return '\0';
} /* end function delete */
/* Return 1 if the list is empty, 0 otherwise */
int isEmpty( ListNodePtr sPtr )
{
return sPtr == NULL;
} /* end function isEmpty */
/* Print the list */
void printList( ListNodePtr currentPtr )
{
/* if list is empty */
if ( currentPtr == NULL ) {
printf( "List is empty.\n\n" );
} /* end if */
else {
printf( "The list is:\n" );
/* while not the end of the list */
while ( currentPtr != NULL ) {
printf( "%c --> ", currentPtr->data );
currentPtr = currentPtr->nextPtr;
} /* end while */
printf( "NULL\n\n" );
} /* end else */
} /* end function printList */
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/*Operating and maintaining a list */
#include <stdio.h>
#include <stdlib.h>
/* self-referential structure */
struct listNode {
char data; /* define data as char */
struct listNode *nextPtr; /* listNode pointer */
}; /* end structure listNode */
typedef struct listNode ListNode;
typedef ListNode *ListNodePtr;
/* prototypes */
void insert( ListNodePtr *sPtr, char value );
char delete( ListNodePtr *sPtr, char value );
int isEmpty( ListNodePtr sPtr );
void printList( ListNodePtr currentPtr );
void instructions( void );
int main()
{
ListNodePtr startPtr = NULL; /* initialize startPtr */
int choice; /* user's choice */
char item; /* char entered by user */
instructions(); /* display the menu */
printf( "? " );
scanf( "%d", &choice );
/* loop while user does not choose 3 */
while ( choice != 3 ) {
switch ( choice ) {
case 1:
printf( "Enter a character: " );
scanf( "\n%c", &item );
insert( &startPtr, item );
printList( startPtr );
break;
case 2:
/* if list is not empty */
if ( !isEmpty( startPtr ) ) {
printf( "Enter character to be deleted: " );
scanf( "\n%c", &item );
/* if character is found */
if ( delete( &startPtr, item ) ) {
printf( "%c deleted.\n", item );
printList( startPtr );
} /* end if */
else {
printf( "%c not found.\n\n", item );
} /* end else */
} /* end if */
else {
printf( "List is empty.\n\n" );
} /* end else */
break;
default:
printf( "Invalid choice.\n\n" );
instructions();
break;
} /* end switch */
printf( "? " );
scanf( "%d", &choice );
} /* end while */
printf( "End of run.\n" );
return 0; /* indicates successful termination */
} /* end main */
/* display program instructions to user */
void instructions( void )
{
printf( "Enter your choice:\n"
" 1 to insert an element into the list.\n"
" 2 to delete an element from the list.\n"
" 3 to end.\n" );
} /* end function instructions */
/* Insert a new value into the list in sorted order */
void insert( ListNodePtr *sPtr, char value )
{
ListNodePtr newPtr; /* pointer to new node */
ListNodePtr previousPtr; /* pointer to previous node in list */
ListNodePtr currentPtr; /* pointer to current node in list */
newPtr = malloc( sizeof( ListNode ) );
if ( newPtr != NULL ) { /* is space available */
newPtr->data = value;
newPtr->nextPtr = NULL;
previousPtr = NULL;
currentPtr = *sPtr;
/* loop to find the correct location in the list */
while ( currentPtr != NULL && value > currentPtr->data ) {
previousPtr = currentPtr; /* walk to ... */
currentPtr = currentPtr->nextPtr; /* ... next node */
} /* end while */
/* insert newPtr at beginning of list */
if ( previousPtr == NULL ) {
newPtr->nextPtr = *sPtr;
*sPtr = newPtr;
} /* end if */
else { /* insert newPtr between previousPtr and currentPtr */
previousPtr->nextPtr = newPtr;
newPtr->nextPtr = currentPtr;
} /* end else */
} /* end if */
else {
printf( "%c not inserted. No memory available.\n", value );
} /* end else */
} /* end function insert */
/* Delete a list element */
char delete( ListNodePtr *sPtr, char value )
{
ListNodePtr previousPtr; /* pointer to previous node in list */
ListNodePtr currentPtr; /* pointer to current node in list */
ListNodePtr tempPtr; /* temporary node pointer */
/* delete first node */
if ( value == ( *sPtr )->data ) {
tempPtr = *sPtr;
*sPtr = ( *sPtr )->nextPtr; /* de-thread the node */
free( tempPtr ); /* free the de-threaded node */
return value;
} /* end if */
else {
previousPtr = *sPtr;
currentPtr = ( *sPtr )->nextPtr;
/* loop to find the correct location in the list */
while ( currentPtr != NULL && currentPtr->data != value ) {
previousPtr = currentPtr; /* walk to ... */
currentPtr = currentPtr->nextPtr; /* ... next node */
} /* end while */
/* delete node at currentPtr */
if ( currentPtr != NULL ) {
tempPtr = currentPtr;
previousPtr->nextPtr = currentPtr->nextPtr;
free( tempPtr );
return value;
} /* end if */
} /* end else */
return '\0';
} /* end function delete */
/* Return 1 if the list is empty, 0 otherwise */
int isEmpty( ListNodePtr sPtr )
{
return sPtr == NULL;
} /* end function isEmpty */
/* Print the list */
void printList( ListNodePtr currentPtr )
{
/* if list is empty */
if ( currentPtr == NULL ) {
printf( "List is empty.\n\n" );
} /* end if */
else {
printf( "The list is:\n" );
/* while not the end of the list */
while ( currentPtr != NULL ) {
printf( "%c --> ", currentPtr->data );
currentPtr = currentPtr->nextPtr;
} /* end while */
printf( "NULL\n\n" );
} /* end else */
} /* end function printList */
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