题解 | #牛牛的链表添加节点#

#include <stdio.h>
#include <stdlib.h>
typedef struct node {
    int data;
    struct node* next;
} Node;
typedef struct list {
    Node* head;
} List;
void print(List* list);
void add(int num, List* list);
void add1(int i, List* list, int n);
int main() {
    int n, i, num;
    List list;
    list.head = NULL;
    scanf("%d %d", &n, &i);
    for (int t = 0; t < n; t++) {
        scanf("%d", &num);
        add(num, &list);
    }
    add1(i, &list, n);
    print(&list);
    return 0;
}
void add(int num, List* list) {
    Node* p = (Node*)malloc(sizeof(Node));
    p->data = num;
    p->next = NULL;
    Node* last = list->head;
    if (list->head) {
        while (last->next) {
            last = last->next;
        }
        last->next = p;
    } else {
        list->head = p;
    }
}
void add1(int i, List* list, int n) {
    if (i == 0) {
        Node* p = (Node*)malloc(sizeof(Node));
        p->data = i;
        p->next = list->head;
        list->head = p;
    } else if (i == n) {
        Node* p = (Node*)malloc(sizeof(Node));
        Node* last = list->head;
        while (last->next) {
            last = last->next;
        }
        p->data = i;
        last->next = p;
    } else {
        Node* pre = NULL;
        Node* cur = list->head;
        Node* p = (Node*)malloc(sizeof(Node));
        p->data = i;
        for (int j = 0; j < i; j++) {
            pre = cur;
            cur = cur->next;
        }
        pre->next = p;
        p->next = cur;
    }
}
void print(List* list) {
    Node* p;
    for (p = list->head; p; p = p->next) {
        printf("%d ", p->data);
    }
}