////删除某一特定节点
public static Node deleteOneNode(Node head, Node delNode) {
if (head == null || delNode == null)
return head;
if (delNode.next == null) {
// 尾节点
Node temp = head;
while (temp.next != null) {
if (temp.next == delNode)
temp.next = delNode.next;
temp = temp.next;
}
} else {
// 非尾节点
Node p = delNode.next;
delNode.value = p.value;
delNode.next = p.next;
}
return head;
}
//删除倒数第n个节点
public static Node removeNthLastNode(Node head, int n) {
if (head == null || n < 0)
return head;
if(n > getListLength(head))
return null;
Node temp = head;
Node target = head;
while (n > 0) {
temp = temp.next;// 定位倒数第n个节点
n--;
}
// System.out.print("temp.value: " + temp.value + " ");
// 删除第一个节点
if (temp == null)
return head.next;
while (temp.next != null) {
target = target.next;// 定位倒数第n+1个节点
temp = temp.next;
}
temp = null;
// System.out.print("target.value: " + target.value + " ");
if (target.next != null)
target.next = target.next.next;
return head;
}
//去除有序链表的重复元素 对于重复元素只保留一个。
public static Node removeDuplicateList(Node head) {
if (head == null || head.next == null)
return head;
Node pre = head;
while (head != null && head.next != null) {
if (head.value == head.next.value) {
head.next = head.next.next;
} else {
head = head.next;
}
}
return pre;
}
//去除有序链表的重复元素 对于重复元素全部删掉 思路一。
public static Node removeDuplicateListAll(Node head) {
if (head == null || head.next == null)
return head;
Node pre = new Node(0);
pre.next = head;
Node fir = pre;// fir保存的是当前节点的前一个节点
Node sec = head;
while (sec != null) {
int value = sec.value;
int count_repeat = 0;
while (sec != null && value == sec.value) {
sec = sec.next;
count_repeat++;// 统计每个节点重复次数
}
if (count_repeat > 1) {// 若出现次数大于1，说明该节点对应的值需要删掉
fir.next = sec;
} else {
fir = fir.next;
}
if (fir != null) {
sec = fir.next;
}
}
return pre.next;
}
//去除有序链表的重复元素 对于重复元素全部删掉。思路二 递归
public static Node deleteDuplication(Node pHead) {
if (pHead == null)
return null;
if (pHead != null && pHead.next == null)
return pHead;
Node current;
if (pHead.next.value == pHead.value) {
current = pHead.next.next;
while (current != null && current.value == pHead.value)
current = current.next;
return deleteDuplication(current);
} else {
current = pHead.next;
pHead.next = deleteDuplication(current);
return pHead;
}
}
