57 lines
1.8 KiB
Java
57 lines
1.8 KiB
Java
package com.zerroi.leetcode.Three25;
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public class DeleteDuplicates {
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public static void main(String[] args) {
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// ListNode head = constructLinkedList(new int[]{1, 2, 3, 3, 4, 4, 5});
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ListNode head = constructLinkedList(new int[]{1, 1});
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SolutionSecond solutionSecond = new SolutionSecond();
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ListNode res = solutionSecond.deleteDuplicates(head);
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while (res != null) {
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System.out.println("res.val = " + res.val);
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res = res.next;
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}
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}
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public static ListNode constructLinkedList(int[] nums) {
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if (nums == null || nums.length == 0) {
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return null;
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}
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ListNode dummy = new ListNode(); // 创建一个虚拟头节点
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ListNode current = dummy;
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for (int num : nums) {
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current.next = new ListNode(num);
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current = current.next;
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}
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return dummy.next; // 返回真正的头节点
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}
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}
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class SolutionSecond {
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public ListNode deleteDuplicates(ListNode head) {
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if (head == null || head.next == null) return head;
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ListNode dummy = new ListNode(-1);
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dummy.next = head;
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// pre指针为cur的前驱节点
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ListNode pre = dummy;
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// cur为当前节点
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ListNode cur = head;
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while (cur != null && cur.next != null) {
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// 如果出现当前节点的值等于其下一节点值，要一直循环找到不相等的
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if (cur.val == cur.next.val) {
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int duplicate = cur.val;
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while (cur != null && cur.val == duplicate) {
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cur = cur.next;
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}
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pre.next = cur;
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} else {
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pre = pre.next;
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cur = cur.next;
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}
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}
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return dummy.next;
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}
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}
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