题解 | #从单向链表中删除指定值的节点#

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

struct ListNode {
public:
    int value;
    shared_ptr<ListNode> next;

    ListNode() :value(-1), next(nullptr) {}
    ListNode(int i) : value(i), next(nullptr) {}

};

void insertANumber(shared_ptr<ListNode> head, int value, int point_value)
{
    auto newNode = make_shared<ListNode>(value);
    while (head!=nullptr)
    {
        if (head->value == point_value)
        {
            auto temp = make_shared<ListNode>();
            temp->next = head->next;
            head->next = newNode;
            newNode->next = temp->next;
            break;
        }
        else
        {
            head = head->next;
        }
    }
}

int deleteNumber(shared_ptr<ListNode> head, int value)
{
    shared_ptr<ListNode> last;
    while (head != nullptr)
    {
        if (head->value == value)
        {
            if (last != nullptr)
            {
                last->next = head->next;
                break;
            }
            else
            {
                return -1;
            }
        }
        else
        {
            last = head;
            head = head->next;
        }
    }
    return 0;
}

int main() {
    int N;
    int headvalue;
    cin>>N>>headvalue;
    shared_ptr<ListNode> head = make_shared<ListNode>(headvalue);
    for(int i = 0;i!=N-1;++i)
    {
        int value,point_value;
        cin>>value>>point_value;
        insertANumber(head, value, point_value);
    }
    cin>>headvalue;
    if(deleteNumber(head, headvalue)==-1)
        head = head->next;
        
    while(head!=nullptr)
    {
        cout<<head->value<<" ";
        head = head->next;
    }
}
// 64 位输出请用 printf("%lld")

最好使用shared_ptr来分配和管理内存。