C语言建立链表

题目：

输入一个单向链表，输出该链表中倒数第k个结点，链表的倒数第1个结点为链表的尾指针。

代码：

#include <cstdio>
#include <cstdlib>
/*
收藏原因：主要可以熟悉用C语言建立链表的过程
*/
struct Node{
    int val;
    struct Node *next;
};
int main(){
    int i, n, t;
    Node *head, *p, *q;
    while(scanf("%d", &n) != EOF){
        head = (struct Node*)malloc(sizeof(Node));
        head->next = NULL;
        p = head;
        for(i=0; i<n; i++){
            q = (struct Node*)malloc(sizeof(Node));
            scanf("%d", &t);
            q->val = t;
            p->next = q;
            p = q;
        }
        scanf("%d", &t);
        if(t>n){
            printf("NULL
");
            continue;
        }else if(t < 1){
            printf("%d
", t);
            continue;
        }
        p = head->next;
        q = p;
        while(t--) p = p->next;
        while(p != NULL){
            p = p->next;
            q = q->next;
        }
        printf("%d
", q->val);
    }
    return 0;
}