Implementation of linked list classes in C ++

Question requirements:

1. Define a linear table class linearlist composed of int elements. It has the following member functions:

Bool insert (int x, int POS); // insert an element x after position POS.
// When POS is 0, insert it before the first element.
// If the operation succeeds, true is returned. Otherwise, false is returned.
Bool remove (Int & X, int POS); // Delete the element at the position POS.
// If the operation succeeds, true is returned. Otherwise, false is returned.
Int element (int pos) const; // returns the element at the position POS.
Int search (int x) const;
// Find the element whose value is X and return the position of the element (The position of the first element is 1 ). If no value is found, 0 is returned.

Int length () const; // returns the number of elements.

For the first time, I wrote my own code. Although I had some help from Wang,

# Include <iostream>
Using namespace STD;
Struct Node
{
Int element;
Node * next;
};

Class linerlist {
Node * head;
Int Len;
Public:
Linerlist () {Len = 0; head = NULL ;}
Bool insert (int x, int POS );
Bool remove (Int & X, int POS );
Int element (int pos) const;
Int search (int x) const;
Int length () const;
Void show ();
};
Bool linerlist: insert (int x, int POS ){
If (Pos <0)
{
Cout <"enter the correct POS value (requires> 0)" <Endl;
Return false;
} Else if (Pos = 0)
{
Node * P = new node;
P-> element = X;
If (Head! = NULL)
{

P-> next = head;
Head = P;
P-> next = NULL;
Len ++;
Return true;
} Else {
Head = P;
P-> next = NULL;
Len ++;
Return true;
}

} Else if (Pos> 0 & Pos <Len)
{
If (Head! = NULL)
{
Node * P = new node;
P-> element = X;
Node * P1 = head, * P2 = head;
For (INT I = 0; I <Pos; I ++)
{
P2 = p1;
P1 = p1-> next;
}
P2-> next = P;
P-> next = p1;
Len ++;
Return true;
} Else {
Node * P = new node;
P-> element = X;
Head = P;
P-> next = NULL;
Len ++;
Return true;
}

} Else {
Node * P = new node;
P-> element = X;
Node * P1 = head;
While (P1-> next! = NULL)
{
P1 = p1-> next;
}
P1-> next = P;
P-> next = NULL;
Len ++;
Return true;
}
}

Bool linerlist: Remove (Int & X, int POS ){
If (Pos <0 | POS> = Len)
{
Cout <"enter the correct POS value! "<Endl;
Return false;
} Else if (Pos = 0)
{
Node * P = head;
X = p-> element;
Head = p-> next;
Len --;
Return true;
} Else if (Pos> 0 & Pos <len-1 ){
Node * P1 = head, * P2 = head;
For (INT I = 0; I <Pos; I ++)
{
P2 = p1;
P1 = p1-> next;
}
P2-> next = NULL;
X = p1-> element;
P1 = p1-> next;
P2-> next = p1;
Len --;
Return true;
} Else
{
Node * P1 = head, * P2 = head;
For (INT I = 0; I <Pos; I ++)
{
P2 = p1;
P1 = p1-> next;
}
P2-> next = NULL;
Len --;
Return true;
}
}

Int linerlist: element (int pos) const {

If (Pos> = Len | POS <0)
{
Cout <"enter the correct POS value" <Endl;
Return-1;
} Else {
Node * P1 = head;
For (INT I = 0; I <Pos; I ++)
{
P1 = p1-> next;
}
Return P1-> element;
}
}

Int linerlist: Search (int x) const {
Node * P = head;
For (INT I = 0; I <Len; I ++)
{
If (p-> element = X)
{
Return I + 1;
}
P = p-> next;
}
Return 0;
}

Int linerlist: length () const {
Return Len;
}

Void linerlist: Show (){
Node * P = head;
While (P! = NULL)
{
Cout <p-> element <"";
P = p-> next;
}
}

Void main (){
Linerlist lList;
LList. insert (1, 0 );
LList. insert (2, 1 );
LList. insert (3, 1 );
LList. insert (4, 5 );
LList. Show ();
Cout <lList. Length () <"";
Int x = lList. Search (2 );
Cout <X;
}