题解 | #输出单向链表中倒数第k个结点#

#include<iostream>
using namespace std;

struct ListNode{
    int m_nKey;
    ListNode* m_pNext;
    ListNode(int x):m_nKey(x),m_pNext(nullptr){}
};

int res(ListNode * head,int N,int k){
    if(k<1 || k>N+1)
        return NULL;

    ListNode * node = head;
    int t=1;
    while(t<=N-k){
        node=node->m_pNext;
        t++;
    }
    return node->m_nKey;
}

int main(){

    int N,n,k,temp;
    while(cin>>N){
        n=N;
        cin>>temp;
        ListNode * root = new ListNode(temp);
        ListNode * node=root;
        n--;
        while(n--){
            cin>>temp;
            ListNode * newNode = new ListNode(temp);
            node->m_pNext=newNode;
            node=node->m_pNext;
        }

        cin>>k;
        cout<<res(root,N,k)<<endl;
    }

    return 0;
}