Pairwise swapping of nodes in a Linked List

//pairwise swapping of linkedlist nodes

//INPUT : 1->2->3->4->5->6->7->8->9->10

// OUTPUT : 2->1->4->3->6->5->8->7->10->9

#include<stdio.h>

#include<stdlib.h>

typedef struct node{

int data;

struct node *next;

}Node;

void pairwiseSwap(Node **headRef){

Node *current = *headRef;

Node *temp;

Node *prev = NULL;

while(current != NULL && current->next != NULL){

temp = current->next;

current->next = temp->next;

temp->next = current;

if(prev != NULL){

prev->next = temp;

}

if(current == *headRef){

*headRef = temp;

}

prev = current;

current = current->next;

}

}

Node* newNode(int data){

Node *n = (Node*)malloc(sizeof(Node));

n->data = data;

n->next = NULL;

return n;

}

void buildList(Node **headRef){

int i;

for(i=10;i>0;i--){

Node *n = newNode(i);

n->next = *headRef;

*headRef = n;

}

}

void freeMem(Node *head){

    Node *temp;

    while(head != NULL){

        temp = head;

        head = head->next;

        free(temp);

    }

}

void display(Node *head){

while(head->next != NULL){

printf("%d->",head->data);

head = head->next;

}

printf("%d\n",head->data);

}

void main(){

Node *head = NULL;

buildList(&head);

display(head);

pairwiseSwap(&head);

display(head);

freeMem(head);

}