重拾算法之剑指Offier——链表中倒数第k个结点

剑指Offier——链表中倒数第k个结点

/*
public class ListNode {
int val;
ListNode next = null;

ListNode(int val) {
this.val = val;
}
}*/
public class Solution {

public ListNode FindKthToTail(ListNode head,int k) {
ListNode p = head;
ListNode pre = head;

int preNumber = k;
int cnt = 0;

while (p != null){
p = p.next;
if (k <= 0){
pre = pre.next;
}
k --;
cnt ++;
}
if(preNumber > cnt){
return null;
}

return pre;
}
}