题解 | #牛牛的链表添加节点#

#include <stdio.h>
#include <stdlib.h>

typedef struct node {
    int num;
    struct node* next;
} Node;

Node* createlist(int num) {
    Node* head = (Node*)malloc(sizeof(Node));
    head->num = num;
    head->next = NULL;
    return head;
}

void add_node(Node* head, int num) {
    Node* p = (Node*)malloc(sizeof(Node));
    p->num = num;
    p->next = NULL;
    Node* q = head;
    while (q->next) {
        q = q->next;
    }
    q->next = p;
}

void Printlist(Node* cur) {
    while (cur) {
        printf("%d ", cur->num);
        cur = cur->next;
    }
}

Node* insert(Node* head,int n,int num)
{
    Node* p=head;
    n-=1;
    while(n--)
    {
        p=p->next;
    }
    Node* q=malloc(sizeof(Node));
    q->num=num;
    q->next=p->next;
    p->next=q;
    return head;
}

int main() {
    int n, i;
    scanf("%d%d", &n, &i);
    int a;
    scanf("%d", &a);
    Node* head = createlist(a);
    for (int j = 1; j < n; j++) {
        scanf("%d", &a);
        add_node(head, a);
    }
    head=insert(head, i, i);
    Printlist(head);
    return 0;
}