TM Double Link List

#include<stdio.h>
#include<Windows.h>

struct data{
    int angka;
    struct data *prev;
    struct data *next;
}*head,*now,*temp,*tail;

void ins(int x){
    now=head;
    for(now=head;now!=NULL;now=now->next){
        if(x>now->angka){
            temp=now;
            now=(struct data*)malloc(sizeof(data));
            now->angka=x;
            now->next=temp;
            now->prev=temp->prev;
            temp->prev=now;
            if(now->prev!=NULL){
                now=now->prev;
                now->next=temp->prev;
            }//kalo dia head
            else
                head=now;
            break;
        }
        else if (now->next==NULL){//kalo tail
            temp=now;
            now=(struct data*)malloc(sizeof(data));
            now->angka=x;
            now->prev=temp;
            now->next=0;
            tail=now;
            temp->next=now;
            break;
        }
    }
}

void intz(int x){
    now=(struct data*)malloc(sizeof(data));
    if(head==0)//data perdana
        tail=now;
    now->angka=x;
    now->next=head;//Double Link list Start
    head=now;
    now->prev=NULL;
    if(now->next!=0){
        temp=now;
        now=now->next;
        now->prev=temp;
    }// Double Link list end
}

void cetak(){
    for(now=tail;now!=NULL;now=now->prev){
        printf("%d",now->angka);
        if (now->prev!=NULL)
            printf(" -> ");
    }
    printf("\n");
}

int main(){

    head=0;
    temp=0;
    printf("Sebelum insert\n");
    intz(1);
    intz(3);
    cetak();
    printf("Setelah insert awal\n");
    ins(5);
    cetak();
    printf("Setelah insert akhir\n");
    ins(0);
    cetak();
    printf("Setelah insert tengah\n");
    ins(2);
    cetak();
    now=head;
    getchar();
}