KidsGame

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

typedef struct N
{
    char pName[50];
    struct N * pNext;
   // struct N * pPrev;
}Node;

typedef struct DLList
{
    int cnt;
    Node * pFirst;
    Node * pLast;
}DLL;

void initList ( DLL ** l)
{
    (*l)->cnt=0;
    (*l)->pFirst = NULL;
   // (*l)->pPrev = NULL;
    //(*l)->pFirst->pNext = NULL;
   // (*l)->pFirst->pPrev = NULL;
    //(*l)->pLast->pNext = NULL;
   // (*l)->pLast->pPrev = NULL;

}

DLL *listPtr;
//
//Node * giveName( DLL ** ppl, char Name[50] )
//{
//    if( (*ppl) )
//    {
//        listPtr->pNext= NULL;// listPtr->pPrev= NULL;
//        strcpy(listPtr->pName,Name);
//        listPtr->pNext = listPtr;
//    }
//    return listPtr;
//}

void insertAtRear ( DLL ** listPtr, char Name[50])
{
        Node* p = (Node*)malloc(sizeof(Node));
        strcpy(p->pName,Name);
        p->pNext = NULL;


        if((*listPtr)->pLast == NULL) /// when the list is EMPTY
        {
            (*listPtr)->pFirst = (*listPtr)->pLast = p;
            p->pNext=(*listPtr)->pFirst;

        }
        else ///when the list is not EMPTY
        {
            (*listPtr)->pLast->pNext = p; // chain after the former last node
            p->pNext = (*listPtr)->pFirst; // p is after the former last node
            (*listPtr)->pLast = p; // p is the last node
        }
        (*listPtr)->cnt++;
}

void deleteNode ( DLL * l, char Name[50])
{
    Node * p;
    Node * prevPtr;
    p = l->pFirst;
    prevPtr = l->pLast;
    int j;
    for( j=0; j < l->cnt; j++)
    {
        if( stricmp ( p->pName, Name) == 0 )
        {
            prevPtr->pNext = p->pNext;
            if( p == l->pFirst)
                l->pFirst = p->pNext;
            if( p == l-> pLast)
                l->pLast = prevPtr;
            l->cnt--;
            break;
        }
        prevPtr=p;
        p = p->pNext;
    }
}

char * Circle ( DLL * l , int nrKids)
{
    while ( l->cnt != 1)
    {
        int counter=1;
        Node *p = l->pFirst;
        while(counter < nrKids && p)
        {
            p = p->pNext;
            counter++;
        }
        deleteNode(l, p->pName);
    }
    return l->pFirst->pName;
}

void Display(DLL *l, int n, FILE *O)
{
    Node *p = l->pFirst;
    if(p == NULL) fprintf(O,"Failed to create the list");
    while(p != NULL)
    {
        int i;
        for(i=0; i<n; i++)
        {
            fprintf(O,"%s \n", p->pName);
            p = p->pNext;
        }
    }

}

int main ()//int argc, int * argv[])
{
    DLL * Game;
    Game = (DLL*) malloc(sizeof(DLL));
    initList(&Game);

    FILE *P = fopen("P.in","r");
    FILE *O = fopen("O.out","w");

    if( P == NULL )
        printf("The input file could not be opened.");
    if ( O == NULL )
        printf("The output file could not be opened.");


    int nrKids, i=0;
    char kidName[1050], junk[50];

    fscanf(P, "%d", &nrKids);
    fgets(junk,50,P);
    fprintf(O, "%d \n", nrKids);

    for(i=0; i<nrKids; i++)
    {
        fscanf(P,"%s", kidName);
        insertAtRear(&Game, kidName);
    }

    Display(Game, nrKids, O);
    fprintf("\n%s\n", Circle(Game, nrKids));

    return 0;
}