Josephus Problem Solution Using Circular Linked List

The problem statement: 

There are n people standing in a circle waiting to be executed. The counting out begins at some point in the circle and proceeds around the circle in a fixed direction. In each step, a certain number of people are skipped and the next person is executed. The elimination proceeds around the circle (which is becoming smaller and smaller as the executed people are removed), until only the last person remains, who is given freedom. Given the total number of persons n and a number k which indicates that k-1 persons are skipped and kth person is killed in circle. The task is to choose the place in the initial circle so that you are the last one remaining and so survive.

 
Josephus Problem Solution Using Circular Linked List in C :

#include<stdio.h>
#include<stdlib.h>
struct node
{
    int num;
    struct node *next;
};
struct node *head=NULL;

void create();
void display();
int survivor(int);

int main()
{
int survive,skip;
create();
display();   
printf("Enter the number of persons to be skipped\n");
scanf("%d",&skip);
survive=survivor(skip);
printf("The person to survive is : %d \n",survive);
free(head);
}

void create()
{
    struct node *temp,*rear;
    int a,ch;
    do
    {
        printf("Enter a number : ");
        scanf("%d",&a);
        temp=(struct node *)malloc(sizeof(struct node));
        temp->num=a;
        temp->next=NULL;
       
        if(head==NULL)
        {
            head=temp;
            temp->next=head;
        }
        else
        {
            rear=head;
            while(rear->next!=head)
            {
                rear=rear->next;
            }
            rear->next=temp;
            temp->next=head;
        }
       
        printf("Do you want to add a number [1/0]?");
        scanf("%d",&ch);
    }
    while(ch!=0);
}

void display()
{
    struct node *temp;
    temp=head;
    do
    {
        printf("%d ",temp->num);
        temp=temp->next;
    }
    while(temp!=head);
    printf("\n");
}


int survivor(int k)
{
    struct node *p,*q;
    int i;
    p=q=head;
    while(p->next!=p)
    {
        for(i=0;i<k-1;i++)
        {
            q=p;
            p=p->next;
        }
        q->next=p->next;
        printf("%d has been killed \n",p->num);
        free(p);
        p=q->next;
    }
    head=p;
    return (p->num);
}