# Program to Combine Two Linked List

## Implementation

Implementation of this algorithm is given below −

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

struct node {
int data;
struct node *next;
};

struct node *even = NULL;
struct node *odd = NULL;
struct node *list = NULL;

void insert(int data) {
// Allocate memory for new node;
struct node *link = (struct node*) malloc(sizeof(struct node));
struct node *current;

if(data%2 == 0) {
if(even == NULL) {
return;
} else {
current = even;

while(current->next != NULL)
current = current->next;

// Insert link at the end of the list
}

} else {
if(odd == NULL) {
return;
} else {
current = odd;

while(current->next!=NULL)
current = current->next;

// Insert link at the end of the list
}
}
}

void display(struct node *head) {
struct node *ptr = head;

while(ptr != NULL) {
printf(" %d =>",ptr->data);
ptr = ptr->next;
}

printf(" [null]\n");
}

void combine() {

list = even;

}

}

int main() {
int i;

for(i = 1; i <= 10; i++)
insert(i);

printf("Even : ");
display(even);

printf("Odd  : ");
display(odd);

combine();

printf("Combined List :\n");
display(list);

return 0;
}
```

## Output

Output of the program should be −

```Even : [head] => 2 => 4 => 6 => 8 => 10 => [null]
Odd  : [head] => 1 => 3 => 5 => 7 => 9 => [null]
Combined List :
[head] => 2 => 4 => 6 => 8 => 10 => 1 => 3 => 5 => 7 => 9 => [null]
```