Linked List Question

**Aliano** · 10-26-2013

In the following code, it required for users to enter scores between 0 -50 which should print valid link list and if values beyond the range are entered, should be flagged as invalid and print invalid list.
Example:
Linked-List of valid scores 0->30->27->43-> END OF VALID LIST
Linked-List of invalid scores 0->55->65->66->END OF ERROR LIST

Here is My Code:
Help Me To Implant this

Code:

#include <Stdio.h>#include <stdlib.h>
#include <malloc.h>


void main()
{
	struct node
	{
		int num;
		struct node *p;
	};
	typedef struct node NODE;
	
	NODE *head, *first, *temp = 0;
	int count = 0;
	int choice = 1;
	first = 0;
	
	while(choice)
	{
		head = (NODE *)malloc(sizeof(NODE));
		printf("Enter the data item\n");
		scanf("%d", &head-> num);
		if(first !=0)
		{
			temp -> p = head;
			temp = head;
		}
		else
		{
			first = temp = head;
		}
		fflush(stdin);
		printf("Do You want to continue (Type 0 or 1)?\n");
		scanf("%d", &choice);
	}
	temp->p=0;
	// reset temp to the begining 
	temp = first;
	printf("\n status of the linked list is\n");
	while(temp !=0)
	{
		printf("%d=>", temp->num);
		count++;
		temp = temp -> p;
	}
	printf("NULL\n");
	printf("No.Of Nodes in the list = %d \n", count);
}

**Salem** · 10-26-2013

> #include <Stdio.h>
It is usual to write filenames in lowercase, even when your local file system seems to ignore case.

> #include <malloc.h>
malloc is in stdlib.h, which you already include (unless you're using some really old fossil compiler).

> void main()
SourceForge.net: Void main - cpwiki

> struct node *p;
The usual convention is to call the link 'next';

> NODE *head, *first, *temp = 0;
head and first pretty much mean the same thing.
temp (within the context of the first loop) should be called tail.

> head = (NODE *)malloc(sizeof(NODE));
FAQ > Casting malloc - Cprogramming.com

> fflush(stdin);
SourceForge.net: Fflush - cpwiki

Now, as for your question, what is hard about
if ( temp->num < 0 || temp->num > 50 )

**Aliano** · 10-27-2013

Code:

#include <stdio.h>#include <stdlib.h>


//Linked List data structure  declaration
struct node
{
	int num;
	struct node *next;
};


// Function Prototype declaration
void create(struct node **);
void display (struct node *);




//Main Program
int main()
{
	struct node *p = NULL;
	
	create(&p);
	display(p);
	
	return 0;
}
// Function to Insert 
void create(struct node **head)
{
	int c,ch;
	struct node *temp, *rear;
	
	do
	{
		printf("Enter Number:");
		scanf("%d", &c);
		temp = (struct node *)malloc(sizeof(struct node));
		temp -> num = c;
		temp -> next = NULL;
		
			if (*head == NULL)
			{
				*head = temp;
			}
			else 
			{
				rear->next = temp;
			}
		
		rear = temp;
		printf("Do you wish to continue [1/0]:");
		scanf("%d", &ch);
	}while(ch !=0);
	printf("\n");	
	}
	
	


void display(struct node *p)
{


if (p->num <0 || p -> num > 50)
	{
		printf("Linked-List of Valid Scores %d =>", p ->num);
		printf("end of VALID list \n");
	}
	else{
		printf("Linked-List of invalid Scores %d =>",p->num);
		printf("end of ERROR-list \n");
	}
}

Can you help me to solve this! display function is not working

**DeadPlanet** · 10-27-2013

I don't know how your display function is supposed to work so I can't tell you why it's not working, it looks like it works fine to me.

One hint though. Your code should add the first node to the list fine, but nodes after that won't be added. Step through your code line by line and you should be able to see why.

**Aliano** · 10-27-2013

Originally Posted by DeadPlanet

I don't know how your display function is supposed to work so I can't tell you why it's not working, it looks like it works fine to me.

One hint though. Your code should add the first node to the list fine, but nodes after that won't be added. Step through your code line by line and you should be able to see why.

In the following code, it required for users to enter scores between 0 -50 which should print valid link list and if values beyond the range are entered, should be flagged as invalid and print invalid list.
I WANT OUTPUT TO BE LIKE THIS:
Linked-List of valid scores 0->30->27->43-> END OF VALID LIST
Linked-List of invalid scores 0->55->65->66->END OF ERROR LIST

**Salem** · 10-27-2013

You had a working display() function in your original post.

All you needed to add to it was a test to record whether (or not) you've seen an out of range value.

When you're done printing, you print the appropriate message.

**Aliano** · 10-27-2013

Originally Posted by Salem

You had a working display() function in your original post.

All you needed to add to it was a test to record whether (or not) you've seen an out of range value.

When you're done printing, you print the appropriate message.

In my first post coding linked list print as the order it is entered! i want to print like this. 0 to 50 scores as valid and rest as invalid :|

Linked-List of valid scores 0->30->27->43-> END OF VALID LIST
Linked-List of invalid scores 0->55->65->66->END OF ERROR LIST

Code:

oid display(struct node *p)
{


if (p->num <0 || p -> num > 50)
    {
        printf("Linked-List of Valid Scores %d =>", p ->num);
        printf("end of VALID list \n");
    }
    else{
        printf("Linked-List of invalid Scores %d =>",p->num);
        printf("end of ERROR-list \n");
    }
}

this part is not working i am new to programming language couldn't figure out

**Aliano** · 10-28-2013

Code:

#include <stdio.h>#include <stdlib.h>


//Linked List data structure  declaration
struct node
{
	int num;
	struct node *next;
};


// Function Prototype declaration
void create(struct node **);
void display_valid(struct node *, const char * );
void display_invalid (struct node *, const char * );


//Main Program
int main()
{
	struct node *p = NULL;
	
	create(&p);
	display_valid(p, "Linked-List of valid Scores => %d");
	display_invalid(p, "Linked-List of invalid Scores => %d");


	return 0;
}
// Function to Insert 
void create(struct node **head)
{
	int c,ch;
	struct node *temp, *rear;
	
	do
	{
		printf("Enter Number:");
		scanf("%d", &c);
		temp = (struct node *)malloc(sizeof(struct node));
		temp -> num = c;
		temp -> next = NULL;
		
			if (*head == NULL)
			{
				*head = temp;
			}
			else 
			{
				rear->next = temp;
			}
		
			rear = temp;
			printf("Do you wish to continue [1/0]:");
			scanf("%d", &ch);
			
			}while(ch !=0);
			
		printf("\n");	
	}


// Function to Display
void display_valid(struct node *p, const char * str)
{
	if(p -> num >= 0 && p -> num <= 50)
	{
		printf(str, p->num);
		
		if ( p-> next)
		{
			display_valid(p->next, "%d");
		}
		else
		{
			if (p->next)
			{
				display_valid(p->next, str);
			}
			else
			{
				fputs("\n", stdout);
			}
		}


}


void display_invalid (struct node *p, const char * str)
{
	if(p -> num<0 || p -> num > 50)
	{
		printf(str, p -> num);
		
		if (p -> next)
		{
			display_invalid(p->next, "%d");
		}
		else
		{
			fputs("\n",stdout);
		}
	}
	else
	{
		if (p -> next)
		{
			display_invalid(p->next, str);
		}
		else
		{
			fputs("\n", stdout);
		}
	}
}

can someone help me to fix this program?
In the following code, it required for users to enter scores between 0 -50 which should print valid link list and if values beyond the range are entered, should be flagged as invalid and print invalid list.
I WANT OUTPUT TO BE LIKE THIS:
Linked-List of valid scores 0->30->27->43-> END OF VALID LIST
Linked-List of invalid scores 0->55->65->66->END OF ERROR LIST

**Salem** · 10-28-2013

This is what you had originally.

Code:

void display ( node *p ) {
  while ( p != NULL ) {
    printf("%d->", p->data);
    p = p->next;
  }
}

Now try this

Code:

void display ( node *p ) {
  while ( p != NULL ) {
    if ( p->data < 0 || p->data > 50 ) fprintf(stderr,"OUT OF RANGE\n");
    printf("%d->", p->data);
    p = p->next;
  }
}

Now, instead of printing something every time, set a flag and print it once at the end.

**rcgldr** · 10-28-2013

Another fix, both head and rear should be in main and passed to the create function ... (struct node **head, struct node **rear) ...

**Aliano** · 10-28-2013

Originally Posted by Salem

This is what you had originally.

Code:

void display ( node *p ) {
  while ( p != NULL ) {
    printf("%d->", p->data);
    p = p->next;
  }
}

Now try this

Code:

void display ( node *p ) {
  while ( p != NULL ) {
    if ( p->data < 0 || p->data > 50 ) fprintf(stderr,"OUT OF RANGE\n");
    printf("%d->", p->data);
    p = p->next;
  }
}

Now, instead of printing something every time, set a flag and print it once at the end.

i didnt get what you mean by "

Now, instead of printing something every time, set a flag and print it once at the end."

i hate linked list -_-

http://i.imgur.com/dtodncW.png

**Salem** · 10-28-2013

I'm curious as to how you managed to create a functional linked list all by yourself, and yet make such a mess over something as trivial as setting a flag and testing it.

A flag is simply a boolean variable, it has two states.

Now figure out a boolean expression that records whether (or not) you've ever seen an out of range value whilst printing your array.

If you don't exclaim "OMG, why didn't I see that before" when you finally get it, then programming isn't for you.

**Aliano** · 10-31-2013

Code:

#include <stdio.h>
#include <stdlib.h>


struct node 
  int no;
  struct node *next;
};


struct node *Valid_List; 
struct node *Invalid_List;


void create(struct node **);


int main()
{
  struct node *p = NULL;
  printf("'q' or 'Q' to end the mark entry!\n");
  create(&p);


if ((p->no < 0) || (p->no > 50))
         {
            Valid_List = p;    
            p = Valid_List -> next;
            printf("%d->", Valid_List-> no);
        }
         else
         {
            Invalid_List = p;
            p = Invalid_List -> next;
            printf("%d->", Invalid_List-> no);
        }
        
  return 0;
}


void create(struct node **head)
{
  int c;
  char ch;
  struct node *temp, *rear;


  do
  {


    printf("Enter Score:");
    scanf("%d", &c);
    temp = (struct node *)malloc(sizeof(struct node));
    temp -> no = c;
    temp -> next = NULL;


    if (*head == NULL)
    {
  *head = temp;
    }
    else
    {
  rear->next = temp;
    }


    rear = temp;
    scanf("%c", &ch);


    } while(ch !='q' && ch !='Q');


  printf("\n");    
}

i want to print as two linked list! so later i can calculate the average lowest highest of valid list range of 0 to 50.
after user input i want to print the valid and invalid linked list by if else condition. i have tried to do it check it in main function.
In header i have declared two pointer for pointing valid and invalid list. Struct node *Invalid_List , Struct node *Valid_List.
I am just a beginner! :/
How to fix this? Helps will be really appreciated

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