linked lists inserting problem

Hi,
I am making a long integer arthimetic calculator that performs +and*. I am adding an element and then printing the node.The problem I am having is that I can the value I inserted but I also get random garbage in front that I never inserted.

For example if I insert 10 I get 0 -38 10
My code is:

Code:

---

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


#include <string.h>
#include <ctype.h>
#define FALSE 0

typedef struct node
{
    int integerone;
    struct node * link;
} list_head;
/* Printing the list Contents */

void printList(list_head*head){
  list_head*temp=head;
  while(temp){
    printf("%d  " ,  temp->integerone);
    temp=temp->link;
  }

}

void Menu(int *choice) {

    char    local;
    printf("\n1.Insert first number\n");
    printf("2. Insert second number\n");
    printf("3. Add numbers\n");
    printf("4. Multiply numbers\n");
    printf("5. Process file\n");
    printf("6. Quit\n");
    printf("Enter Option: ");
    do {
        local = getchar ();
    } while (isdigit ((unsigned char) local) == FALSE);
    *choice = (int) local - '0';
}



int insert_to_list(list_head**head,int digit){
    list_head *tmp;
    tmp=NULL;
    tmp = malloc(sizeof(list_head));

  tmp->integerone=digit;
  tmp->link=NULL;

  if(*head==NULL){
      *head=tmp;
  }
          else{
            list_head*temp=*head;
                  while(temp->link!=NULL){
                  temp=temp->link;}
                  temp->link=tmp;
                  return *head;
      }
  }



//allocate memory for a new list header
list_head *create_list(void){
list_head*p=NULL;
p=malloc(sizeof(list_head));

                p->link=NULL;

return p;
}
int main(void){
list_head *head=NULL;
int choice;
char c;

head=create_list();

  do {
        Menu (&choice);
        switch (choice) {
            case 1:
                printf("1. Insert first number\n");
                        scanf("%c",&c);
                                do{

                    head=insert_to_list(&head,c-'0');
                                }while((c = getchar()) != '\n');
                    break;
            case 2:
                printf("2.print list\n");
                                    printList(head);

                break;
            case 3:
                printf("3. Add numbers\n");

                break;

            case 4:
                break;
                printf("4. Multiply numbers\n");

            case 5:
                printf("5. Process file\n");
                break;

            case 6:
                break;
            default:
                printf ("Invalid menu choice - try again\n");
                break;
        }
    } while (choice != 6);

}

---

does anybody have an idea what is wrong.

Well apart from the terrible formatting of your code on the board, read the comments

Code:

---

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

#define FALSE 0

typedef struct node
{
  int integerone;
  struct node * link;
} list_head;
/* Printing the list Contents */

void printList(list_head*head){
  list_head*temp=head;
  while(temp){
    printf("%d  " ,  temp->integerone);
    temp=temp->link;
  }

}

/*!! this list of choices is inconsistent with the cases */
/*!! in main */
void Menu(int *choice) {

  char    local;
  printf("\n1.Insert first number\n");
  printf("2. Insert second number\n");
  printf("3. Add numbers\n");
  printf("4. Multiply numbers\n");
  printf("5. Process file\n");
  printf("6. Quit\n");
  printf("Enter Option: ");
  do {
    local = getchar ();
  } while (isdigit ((unsigned char) local) == FALSE);
  *choice = (int) local - '0';
}

void/*!!int*/ insert_to_list(list_head**head,int digit){
  list_head *tmp;
  /*!!tmp=NULL;*/
  tmp = malloc(sizeof(list_head));

  tmp->integerone=digit;
  tmp->link=NULL;

  if(*head==NULL){
    *head=tmp;
  }
  else{
    list_head*temp=*head;
    while(temp->link!=NULL){
      temp=temp->link;
    }
    temp->link=tmp;
    /*!!return *head;*/
  }
}

/*allocate memory for a new list header*/
/*!! this function is not needed */
list_head *create_list(void){
  list_head*p=NULL;
  p=malloc(sizeof(list_head));

  p->link=NULL;

  return p;
}

int main(void){
  list_head *head=NULL;
  int choice;
  char c;

  /*!!head=create_list();*/

  do {
    Menu (&choice);
    switch (choice) {
      case 1:
        printf("1. Insert first number\n");
        scanf("%c",&c);
        do{
          /*!!head=*/insert_to_list(&head,c-'0');
        } while((c = getchar()) != '\n');
        break;
      case 2:
        printf("2.print list\n");
        printList(head);
        break;
      case 3:
        printf("3. Add numbers\n");
        break;
      case 4:
        break;/*!!unreachable code*/
        printf("4. Multiply numbers\n");
      case 5:
        printf("5. Process file\n");
        break;
      case 6:
        break;
      default:
        printf ("Invalid menu choice - try again\n");
        break;
    }
  } while (choice != 6);
  return 0;/*!!added*/
}

---

The biggest problem seemed to be the way your insert_list function failed to return anything some of the time, and returned things of the wrong type at other times, resulting in a mashed list.

thanks for the help but there is one more problem it still prints
-38 . I don't undertand where is -38 coming from.

Outside of tons of gross coding errors, the following lines irked me the most

Code:

---

list_head *create_list(void){
  list_head*p=NULL;  /*this sort of irks me, but whatever*/
  p=malloc(sizeof(list_head));

  p->link=NULL;
 /*You need to allocate memory for p->link*/

 /*now p has to point to the next node in the list*/
  return p;
}

---

First, you don't check malloc() for NULL. However, that is the least of your immediate worries in this case. You allocate memory for p, but not for p->link. On top of that, you need to then have p point to p->link (ie p = p->link).

Second, the prototype for getchar() is

Code:

---

int getchar(void);

---

In other words, don't go

Code:

---

char c;

c = getchar();

---

It should be
int c;

Third, scanf() blows. If you must use it, at least check for junk values.

> I don't undertand where is -38 coming from.
It's the newline you push onto the list
'\n' - '0' is -38

Try

Code:

---

while((c = getchar()) != '\n') {
  insert_to_list(&head,c-'0');
}

---