chèn/xóa vào đầu hoặc cuối / bất kỳ trong danh sách

//A -> B -> C -> D
//[0] -> [1] -> [2] -> [3]
#include <iostream>

using namespace std;

//2 1
struct Node{
 int data;
 Node *next;
};

Node * dau;
Node * cuoi;

//chen vao cuoi danh sach lien ket
void insertCuoi(Node * node){
 cuoi -> next = node;
 cuoi = node;
}

void inputChenVaoCuoi(){
 //1-10
 dau = new Node();
 dau->data = 1;
 dau->next = NULL;
 cuoi = dau;


 for(int i = 2; i <= 10; i++){
  Node *b = new Node();
  b->data = i;
  b->next = NULL;
  insertCuoi(b);
 }
}

void insertDau(Node * node){
 //2 -> 1
 // a = b;
 node -> next = dau;
 dau = node;
}

void inputChenVaoDau(){
 //1-10
 dau = new Node();
 dau->data = 1;
 dau->next = NULL;
 cuoi = dau;


 for(int i = 2; i <= 10; i++){
  Node *b = new Node();
  b->data = i;
  b->next = NULL;
  insertDau(b);
 }
}


// 1 -> 2 -> 4 -> 5
// 3
//1 -> 2 -> 3 -> 4 ->5

void insertBatKy(int x, Node * node){
 int index = 1;
 Node * p = dau;
 while(p != NULL){
  if(index == x){
   //vi tri can chen
   Node * tmp = p->next;
   p -> next = node;
   node -> next = tmp;
   break;
  }
  p = p -> next;
  index++;
 }
}

void xoadau(){
 Node *p = dau;
 dau  = dau -> next;
 p = NULL;
}
//1 -> 2 -> 3
void xoacuoi(){
 for(Node *i = dau; i != cuoi; i = i -> next){
  if( i -> next == cuoi){
   cuoi = i;
   i -> next = NULL;
   break;
  }
 }
}

// 2-> 3-> 5-> 7

xoabatky(int x){
 int index = 1;
 for(Node *i = dau; i != cuoi; i = i -> next){
  if(index == x){
   i -> next = i -> next -> next;
   break;
  }
  index++;
 }
}

void print(){
 Node * p = dau;
 cout << endl;
 while(p != NULL){
  cout << p -> data << " ";
  p = p -> next;
 }
}

int main(){
 insertBatKy(3, p);
 print();
// xoadau();
// xoacuoi();
 xoabatky(2);
 print();
 return 0;
}