operation.cpp

#include "list.h"
#include "operation.h"


void insert_sorted(List &L, infotype x) {
    /**
    * IS : List may be empty
    * PR : insert an infotype x into an already sorted List L
    *      so that the elements inside List L is still sorted in ascending order,
    *      procedure must also check if such number is already exists (No Duplicate number),
    *      allocate new element only if the conditions are met
    * FS : elements in List L sorted in ascending order, x is inside List L
    */


    address Q,P;
    if((first(L)==NULL) || (x<info(first(L)))) {
        P = allocate(x);
        insertFirst(L,P);
    } else if(findElm(L,x)==NULL){
        Q = first(L);
        while((next(Q)!=NULL) && (x>info(next(Q)))){
            Q = next(Q);
            if(next(Q)==NULL){
                P = allocate(x);
                insertLast(L,P);
            } else if(info(P)!=info(Q)){
                P = allocate(x);
                insertAfter(L,P,Q);
            }
        }

    }
}