题解 | #牛牛的链表添加节点#

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

//链表结点的定义
struct Node {
    int num;
    struct Node* Next;
};

//创建头结点
struct Node* creatList() {
    struct Node* headnode;
    headnode = (struct Node*)malloc(sizeof(struct Node));
    headnode->num = 0;
    headnode->Next = NULL;
    return headnode;
}

//创建结点
struct Node* creatnode(int num) {
    struct Node* newnode;
    newnode = (struct Node*)malloc(sizeof(struct Node));
    newnode->num = num;
    newnode->Next = NULL;
    return newnode;
}

int main() {
    int n, num, i;
    scanf("%d %d\n", &n, &i);

    struct Node* L = creatList();
    struct Node* q = L;

    while (scanf("%d ", &num) != EOF) {
        struct Node* p = creatnode(num);

        //尾插法
        q->Next = p;
        q = p;
    }

    //找到第i个结点
    q = L;
    num = i;
    while (i > 0) {
        q = q->Next;
        i--;
    }

    //创建值为i的结点并插入
    struct Node* p = creatnode(num);
    p->Next = q->Next;
    q->Next = p;

    for (struct Node* p = L->Next; p != NULL ; p = p->Next) {
        printf("%d ", p->num);
    }
    return 0;
}