Q:

# Count the number of occurrences of an element in a linked list without using recursion

Data structure used:

Singly linked list where each node contains a data element say data and the address of the immediate next node say next, with Head holding the address of the first node.

Pseudo code:

```    Begin
Count = 0
while(temp != NULL)
begin
if(temp->data = key)
count=count+1
endif
End while
End
```

### C program to Count the number of occurrences of an element in a linked list without using recursion

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

typedef struct list  //linked list node
{
int data;
struct list *next;
}node;

int main()
{
int choice,count=0,key;

do
{
temp=(node *)malloc(sizeof(node));
if(temp!=NULL)
{
printf("\nEnter the element in the list : ");
scanf("%d",&temp->data);
temp->next=NULL;
{
}
else
{
while(temp1->next!=NULL)
{
temp1=temp1->next;
}
temp1->next=temp;
}
}
else
{
printf("\nMemory not avilable...node allocation is not possible");
}
printf("\nIf you wish to add m ore data on the list enter 1 : ");
scanf("%d",&choice);
}while(choice==1);

//finding occurence of key
printf("\nEnter the data to find it's occurrence : ");
scanf("%d",&key);

while(temp!=NULL)
{
if(temp->data==key)
{
count=count+1;
}
temp=temp->next;
}
printf("\n %d occurred %d times in the list",key,count);

return 0;
}``````

Output

```Enter the element in the list : 1

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 2

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 3

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 4

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 1

If you wish to add m ore data on the list enter 1 : 0

Enter the data to find it's occurrence : 1

1 occurred 2 times in the list
```