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算法思维系列/双指针技巧.md

@@ -446,6 +446,7 @@ String longestPalindrome(String s) {
 | [267. Palindrome Permutation II](https://leetcode.com/problems/palindrome-permutation-ii/?show=1)🔒 | [267. 回文排列 II](https://leetcode.cn/problems/palindrome-permutation-ii/?show=1)🔒 |
 | [281. Zigzag Iterator](https://leetcode.com/problems/zigzag-iterator/?show=1)🔒 | [281. 锯齿迭代器](https://leetcode.cn/problems/zigzag-iterator/?show=1)🔒 |
 | [42. Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/?show=1) | [42. 接雨水](https://leetcode.cn/problems/trapping-rain-water/?show=1) |
+| [543. Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/?show=1) | [543. 二叉树的直径](https://leetcode.cn/problems/diameter-of-binary-tree/?show=1) |
 | [658. Find K Closest Elements](https://leetcode.com/problems/find-k-closest-elements/?show=1) | [658. 找到 K 个最接近的元素](https://leetcode.cn/problems/find-k-closest-elements/?show=1) |
 | [80. Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/?show=1) | [80. 删除有序数组中的重复项 II](https://leetcode.cn/problems/remove-duplicates-from-sorted-array-ii/?show=1) |
 | [82. Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/?show=1) | [82. 删除排序链表中的重复元素 II](https://leetcode.cn/problems/remove-duplicates-from-sorted-list-ii/?show=1) |