list.cpp

#include "list.h"

void createList(List &L) {
    /**
    * FS : set first(L) with Null
    */
    //-------------your code here-------------
    first(L)=NULL;
    //----------------------------------------
}

address allocate(infotype x) {
    /**
    * FS : return new list element with info = x and next element is Null
    */
    address P = NULL;
    //-------------your code here-------------
    P = new elmlist;
    info(P) = x;
    next(P)= NULL;
    //----------------------------------------
    return P;
}

void deallocate(address &P) {
    /**
    * FS : delete element pointed by P
    */
    //-------------your code here-------------
    delete P;
    //----------------------------------------
}

void insertFirst(List &L, address P) {
    /**
    * IS : List L may be empty
    * FS : element pointed by P became the first element in List L
    */
    //-------------your code here-------------
    if(first(L)!=NULL){
        next(P)=first(L);
    }
    first(L)=P;
    //----------------------------------------
}

void insertLast(List &L, address P) {
    /**
    * IS : List L may be empty
    * FS : element pointed by P became the last element in List L
    */
    //-------------your code here-------------
    address Prec;
    Prec=first(L);
    if (first(L)== NULL){
        insertFirst(L,P);
    }else {
        while (next(Prec) != NULL){
            Prec=next(Prec);
        }
        insertAfter(L,Prec,P);
    }
    //----------------------------------------
}

address findElm(List L, infotype x) {
    /**
    * IS : List L may be empty
    * FS : returns element with info.ID = x.ID,
           return Null if such ID is not found
    */

    address P;
    //-------------your code here-------------
    P=first(L);
    while(P!=NULL && info(P)!=x){
        P=next(P);
    }
    //----------------------------------------
    return P;
}

void deleteFirst(List &L, address &P) {
    /**
    * IS : List L may be empty
    * FS : first element in List L is removed and is pointed by P
    */
    //-------------your code here-------------
    P=first(L);
    if (next(P) != NULL){
        first(L)=next(P);
    } else {
        first(L)=NULL;
    }
    //----------------------------------------
}

void deleteLast(List &L, address &P) {
    /**
    * IS : List L may be empty
    * FS : last element in List L is removed and is pointed by P
    */
    //-------------your code here-------------
    address Prec;
    Prec=first(L);
    if (next(Prec)== NULL){
        first(L) = NULL;
    } else {
        while (next(next(Prec)) != NULL){
               Prec=next(Prec);
        }
        P = next(Prec);
        next(Prec) = NULL;
    }
    //----------------------------------------
}

void printInfo(List L) {
    /**
    * FS : view info of all element inside List L,
    *      call the view_data function from my_data.h to print the info
    */
    //-------------your code here-------------
    address P;
    P = first(L);
    while(P!=NULL){
        cout<<info(P)<<", ";
        P=next(P);
    }
    //----------------------------------------
    cout<<endl;
}


void insertAfter(List &L, address Prec, address P) {
    /**
    * IS : Prec and P is not NULL
    * FS : element pointed by P is placed behind the element
    *      pointed by pointer Prec
    */
    //-------------your code here-------------
    if (next(Prec)!=NULL){
        next(P)=next(Prec);
    }
    next(Prec)=P;
    //----------------------------------------

}
void deleteAfter(List &L, address Prec, address &P) {
    /**
    * IS : Prec is not NULL
    * FS : element which was before behind an element pointed by Prec
    *      is removed and pointed by pointer P
    */
    //-------------your code here-------------
    P=next(Prec);
    if (next(P)!=NULL){
        next(Prec)=next(P);
    } else{
        next(Prec)=NULL;
    }
    //----------------------------------------
}