Linked List
A linked list is a data structure which is built from structures and pointers. It forms a chain of "nodes" with pointers representing the links of the chain and holding the entire thing together.
struct Node{
int data_;
Node* next_;
}
The important part of the structure is the line before the closing curly brackets. This gives a pointer to the next node in the list. This is the only case in C++ where you are allowed to refer to a data type (in this case node) before you have even finished defining it!
//if add node at the front
void addFront(int v){
Node* newnode = new Node;
newnode->data_ = v;
if(!start_){
start_ = newnode;
newnode->next_ = NULL;
}
else{
newnode->next_ = start_;
start_ = newnode;
}
}

//if add node at the end
void addEnd(int v){
NOde* temp, temp2;
temp = new Node;
temp->data- = v;
temp->next_ = NULL;
if(!start_) start_ = temp;
else{
temp2 = start_;
while(temp2->next_){
temp2 = temp2->next_;
}
temp2->next_ = temp;
}
}