Member Avatar for YoTaMiX

Hello :-)

I have build a task of Linked List but for some reason , after i break the Input sequence by entering the same INT value twice in a row , the menu appears twice . howcome?

Thank , Code Attached .

Yotam

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

typedef struct list_node
{
int data;
struct list_node *next;
}LIST_NODE,*LIST_NODE_PTR;

typedef struct mid_list
{
LIST_NODE* head;
LIST_NODE* end;
LIST_NODE* biggest;
int size;
}MID_LIST,*MID_LIST_PTR;

int add_value(MID_LIST_PTR list, int new_info);
int get_first_value(MID_LIST parm);
int get_last_value(MID_LIST parm);
int get_items_number(MID_LIST parm);
int the_biggest(MID_LIST parm);
void print_nodes(MID_LIST parm);
void menu();

int main()
{
char choise='1';
int input;
MID_LIST data_list;
MID_LIST_PTR data_list_ptr;

data_list.head=data_list.end=data_list.biggest=NULL;
data_list.size=0;
data_list_ptr=&data_list; 

while (choise!='7')
 {

  menu();

  scanf("%c",&choise);

  switch(choise)
  {
   case '1': { printf("Please enter Data into Node \n"); 
               scanf("%d",&input);
	       while (add_value(data_list_ptr,input)==1)
                    {
                     printf("Please enter Data into Node \n"); 
                     scanf("%d",&input); 
		    }              
                  break;
                } 
   case '2': { printf("Printing Nodes \n"); print_nodes(data_list);break; }
   case '3': { printf("Printing Last Node : %d \n",get_last_value(data_list));break; } 
   case '4': { printf("printing First Node : %d \n",get_first_value(data_list));break; }
   case '5': { printf("Printing Biggest Node Value : %d \n",the_biggest(data_list));break; }
   case '6': { printf("Printing Number of Nodes : %d \n",get_items_number(data_list));break; }
   case '7': { printf("Now Exiting , thank you for using HW_4! \n"); exit(1);break; }
  }
 }
return 0;
}

void menu(void)
{
  printf("Press 1 to add the node to the linked list\n");
  printf("Press 2 to print the nodes\n");
  printf("Press 3 for the last node\n");
  printf("Press 4 for the first node\n");
  printf("Press 5 for the biggest number\n");
  printf("Press 6 for the number of nodes in list\n");
  printf("Press 7 to exit\n");
}

int get_first_value(MID_LIST parm)
{
return parm.head->data;
}

int get_last_value(MID_LIST parm)
{
return parm.end->data;
}

int get_items_number(MID_LIST parm)
{
return parm.size;
}

int the_biggest(MID_LIST parm)
{
LIST_NODE* ptr=NULL;
int max;

ptr=parm.head;
max=ptr->data;

 while (ptr!=NULL)
   {
    if (ptr->data>max) max=ptr->data;
    ptr=ptr->next;
   }
return max;
}

int add_value(MID_LIST_PTR list, int new_info)
{
  LIST_NODE *temp;

temp=(LIST_NODE*)malloc(sizeof(LIST_NODE));
if (temp==NULL)
 {
   printf("\n Not enough memory for the allocation");
   exit(1);
 }
if (new_info!=list->end->data)
  {
  temp->data=new_info;
  temp->next=NULL;
  if (list->head==NULL) list->head=temp;
   else list->end->next=temp;
  list->end=temp;
  list->size+=1;
  return 1;
  }
return 0;
}

void print_nodes(MID_LIST parm)
{
 int i=1;
 LIST_NODE* ptr=NULL;
 ptr=parm.head;

 while (ptr!=NULL)
   {
    printf("Node numder %d - data is %d : \n",i,ptr->data);
    ptr=ptr->next;
    i++;
   }

}
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  • Latest Post Latest Post by Ancient Dragon
Member Avatar for Ancient Dragon

because the keyboard buffer still contains the <Enter> key -- you need to flush that out. One way is like below, which will remove up to 3 keys.

char inbuf[4];
  menu();
  fgets(inbuf,sizeof(inbuf),stdin);
  //scanf("%c",&choise);
  choise = inbuf[0];
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