题解 | 【模板】链表

C++

#include <cstddef>
#include <cstdlib>
#include <iostream>
using namespace std;

using list = struct list {
    int data;
    list *next;
};

list *initList() {
    list *L = new list;
    L->next = nullptr;	// 空头结点
    return L;
}

list* insertList(list *L, int x, int y) {
    list *p = new list;
    list *q = L;
    while (q->next != nullptr && q->next->data != x) {
        q = q->next;
    }
    p->data = y;
    p->next = q->next;
    q->next = p;
    return L;
}

list* deleteList(list *L, int x) {
    list *q = L;
    while (q->next != nullptr) {
        if (q->next->data == x) {
            list *p = q->next;
            q->next = p->next;
            delete p;
            return L;
        }
        q = q->next;
    }
    return L;
}

bool isEmptyList(list *L) {
    return L->next == nullptr;
}

void printList(list *L) {
    list *q = L->next;
    while (q != nullptr) {
        cout << q->data << ' ';
        q = q->next;
    }
}

int main() {
    int n;
    cin >> n;
    string op;
    int x, y;
    list *L = initList();
    while (n--) {
        cin >> op;
        if (op=="insert") {
            cin >> x >> y;
            insertList(L, x, y);
        }
        else if (op=="delete") {
            cin >> x;
            deleteList(L, x);
        }
    }
    if (isEmptyList(L)) cout << "NULL";
    else printList(L);
}
// 64 位输出请用 printf("%lld")