刷题复习（二）数组-双指针
https://labuladong.gitee.io/algo/di-ling-zh-bfe1b/shuang-zhi-fa4bd/
1、删除有序数组中的重复项
慢指针用于统计不重复项，快指针用于不停前进对比是否有新的不重复项，有的话进行替换
class Solution {
public int removeDuplicates(int[] nums) {
int i = 0, j = i + 1;
while (i <= nums.length - 1 && j <= nums.length - 1) {
if (nums[i] != nums[j]) {
i++;
nums[i] = nums[j];
}
j++;
}
return i + 1;
}
}
2、删除排序链表中的重复元素
和上面的数组比较类似
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode deleteDuplicates(ListNode head) {
if(head == null) return head;
ListNode fast = head;
ListNode slow = head;
while (fast != null) {
if (fast.val != slow.val) {
slow.next =fast;
slow =slow.next;
}
fast = fast.next;
}
slow.next = null;
return head;
}
}
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