#include <iostream>
#include <string>
using namespace std;


struct ele {
int dana;
ele * nast;
ele * poprz;
};


void insert(ele* &head, ele* &tail, int x){
	
	ele* nowy = new ele {x,NULL, NULL};
	cout << "Dodalem: " << x << endl; 
	if(head==NULL){
		head = nowy;
		tail = nowy;
		return;
	}
	nowy->poprz = tail;
	tail->nast = nowy;
	tail = nowy;
}

void removeFirst(ele* &head, ele* &tail){
	if(head == NULL){
		cout << "Lista pusta" << endl;
		return;
	}

		else{
		ele* temp = head;
		head = head->nast;
		cout << "Usunalem: " << temp->dana << endl;
		delete temp;
		temp = NULL;
		return;
	}
}

void remove(ele* &head, ele* &tail, int i){
	
	ele* temp = head;
	
	if(head == NULL){
		return;
	}
	if(i == 0){
		head = head->nast;
		delete temp;
		temp = NULL;
		return;
	}
	else{
		int j = 0;
		while (j!=i){
			j++;
			temp=temp->nast;
		}
		temp->poprz->nast =temp->nast;
		temp->nast->poprz = temp->poprz;
		delete temp;
		temp = NULL;
		return;
	}
}

void display(ele* &head, ele* &tail){
	
	if(head == NULL){
		cout << "Lista pusta";
	}
	
	ele* temp = head;

	while(temp){
		cout << temp->dana << " ";
		temp=temp->nast;
	}
}



int main(int argc, char** argv) {
	
	ele* head = NULL;
	ele* tail = NULL;
	
	insert(head, tail, 5);
	insert(head, tail, 10);
	insert(head, tail, 15);
	insert(head, tail, 20);
	remove(head, tail, 2);
	remove(head, tail, 0);
	
	cout << "Lista: ";
	display(head, tail);

	
	return 0;
}