BJFUOJ-300

查找链表倒数第k个结点

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

LinkList TailInsert(int n){
    ListNode* head = new ListNode;
    ListNode* r  = head;
    for(int i = 0;i<n;i++){
        int x;
        cin>>x;
        ListNode* p = new ListNode (x);
        r->next = p;
        r = p;
    }
    r->next = nullptr;
    return head;
}
void find_k(LinkList L,int k){
    ListNode* p = L->next;
    ListNode* q  = p;
    while(q && k){
        q = q->next;
        k--;
    }
    if(k!=0) return ;
    while(q){
        p = p->next;
        q = q->next;
    }
    cout<<p->val<<endl;
}
int main(){

    int n;
    while(cin>>n && (n!=0)){
        LinkList L = TailInsert(n);
        int k;
        cin>>k;
        find_k(L,k);
    }
    return 0;
}