2.3 Implement an algorithm to delete a node in the middle of a singly linked list, given only access to that node.

2.3.cpp

#include<iostream>

using namespace std;

struct Node
{
    int data;
    Node *next;
    
    Node(int data, Node *next) {
        this->data = data;
        this->next = next;
    }
    
    ~Node() {}
};

typedef Node* pNode;

void delNode(pNode p)
{
    if (p == nullptr || p->next == nullptr) return;
    
    pNode t = p->next;
    p->data = t->data;
    p->next = t->next;
    
    delete t;
}

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

void clear(Node *head)
{
    if (head != nullptr) {
        while(head->next != nullptr) {
            Node *t = head->next;
            head->next = t->next;
            delete t;
        }
        delete head;
    }
}

int main(int argc, char *argv[])
{
    Node *list = new Node(0, new Node(1, new Node (2, new Node(3, new Node(4, nullptr)))));
    print(list);
    delNode(list->next->next->next);
    print(list);
    clear(list);
    return 0;
}