题解 | #牛牛的链表添加节点#

#include <iostream>
using namespace std;
struct Node
{
    int val;
    Node* next;
    Node(): val(0), next(nullptr) {}
    Node(int val): val(val), next(nullptr) {}
    Node(int val, Node* next): val(val), next(next) {}
} ;

void createList(Node* dummy, int n)
{
    int i = 0;
    Node* node = dummy;
    while (i != n)
    {
        int d;
        cin >> d;
        node->next = new Node(d);
        node = node->next;
        i++;
    }
}
void addListNode(Node* dummy, int i)
{
    Node* node = dummy;
    int cnt = 0;
    while (node->next != nullptr)
    {   
        if (cnt == i)
        {
            Node* temp = new Node(i);
            temp->next = node->next;
            node->next = temp;
            break;
        }
        else
            cnt++;
        node = node->next;
    }
    if (node->next == nullptr && cnt == i)
        node->next = new Node(i);
}
void printList(Node* dummy)
{
    Node* node = dummy->next;
    while (node != nullptr)
    {
        cout << node->val << " ";
        node = node->next;
    }
}

int main() {
    int n, i;
    cin >> n >> i;
    Node* dummy = new Node();
    createList(dummy, n);
    addListNode(dummy, i);
    printList(dummy);
    return 0;

}
// 64 位输出请用 printf("%lld")

要考虑在末尾添加的情况