From 1f813d446f9d8a3710576f579200114f75e2ee8a Mon Sep 17 00:00:00 2001 From: Jijie LIU Date: Tue, 22 Jun 2021 17:22:42 +0200 Subject: [PATCH 01/12] =?UTF-8?q?update=20406=20=E6=A0=B9=E6=8D=AE?= =?UTF-8?q?=E8=BA=AB=E9=AB=98=E9=87=8D=E5=BB=BA=E9=98=9F=E5=88=97:=20?= =?UTF-8?q?=E7=A7=BB=E9=99=A4Pyhton=E7=89=88=E6=9C=AC=E7=9A=84=E5=86=97?= =?UTF-8?q?=E4=BD=99=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0406.根据身高重建队列.md | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/problems/0406.根据身高重建队列.md b/problems/0406.根据身高重建队列.md index 9aca5b94..946c41ce 100644 --- a/problems/0406.根据身高重建队列.md +++ b/problems/0406.根据身高重建队列.md @@ -214,13 +214,10 @@ Python： ```python class Solution: def reconstructQueue(self, people: List[List[int]]) -> List[List[int]]: - people.sort(key=lambda x: (x[0], -x[1]), reverse=True) + people.sort(key=lambda x: (-x[0], x[1])) que = [] for p in people: - if p[1] > len(que): - que.append(p) - else: - que.insert(p[1], p) + que.insert(p[1], p) return que ``` From ac40cc8be29fdbf22b2b6a5b889315de74f602c3 Mon Sep 17 00:00:00 2001 From: KailokFung Date: Wed, 23 Jun 2021 10:24:40 +0800 Subject: [PATCH 02/12] =?UTF-8?q?fix(1047):=20=E6=96=B0=E5=A2=9E=E5=8F=8C?= =?UTF-8?q?=E6=8C=87=E9=92=88java=E5=86=99=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...除字符串中的所有相邻重复项.md | 23 +++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/problems/1047.删除字符串中的所有相邻重复项.md b/problems/1047.删除字符串中的所有相邻重复项.md index 305a287d..4f13cda3 100644 --- a/problems/1047.删除字符串中的所有相邻重复项.md +++ b/problems/1047.删除字符串中的所有相邻重复项.md @@ -171,6 +171,29 @@ class Solution { } ``` +拓展：双指针 +```java +class Solution { + public String removeDuplicates(String s) { + char[] ch = s.toCharArray(); + int fast = 0; + int slow = 0; + while(fast < s.length()){ + // 直接用fast指针覆盖slow指针的值 + ch[slow] = ch[fast]; + // 遇到前后相同值的，就跳过，即slow指针后退一步，下次循环就可以直接被覆盖掉了 + if(slow > 0 && ch[slow] == ch[slow - 1]){ + slow--; + }else{ + slow++; + } + fast++; + } + return new String(ch,0,slow); + } +} +``` + Python： ```python3 class Solution: From 625558094da614c5f9a2b358f3291bf102f7e1a7 Mon Sep 17 00:00:00 2001 From: KailokFung Date: Wed, 23 Jun 2021 10:31:45 +0800 Subject: [PATCH 03/12] =?UTF-8?q?fix(1047):=20=E4=BD=BF=E7=94=A8ArrayDeque?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/1047.删除字符串中的所有相邻重复项.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/problems/1047.删除字符串中的所有相邻重复项.md b/problems/1047.删除字符串中的所有相邻重复项.md index 4f13cda3..760a0946 100644 --- a/problems/1047.删除字符串中的所有相邻重复项.md +++ b/problems/1047.删除字符串中的所有相邻重复项.md @@ -127,7 +127,9 @@ Java： ```Java class Solution { public String removeDuplicates(String S) { - Deque deque = new LinkedList<>(); + //ArrayDeque会比LinkedList在除了删除元素这一点外会快一点 + //参考：https://stackoverflow.com/questions/6163166/why-is-arraydeque-better-than-linkedlist + ArrayDeque deque = new ArrayDeque<>(); char ch; for (int i = 0; i < S.length(); i++) { ch = S.charAt(i); From cfca263b917143367385184f39be97ce0e4f8233 Mon Sep 17 00:00:00 2001 From: Yan Wen Date: Wed, 23 Jun 2021 16:26:43 +0800 Subject: [PATCH 04/12] =?UTF-8?q?update=E5=8F=8D=E8=BD=AC=E5=AD=97?= =?UTF-8?q?=E7=AC=A6=E4=B8=B2=EF=BC=8C=E6=B7=BB=E5=8A=A0=E4=BA=86python?= =?UTF-8?q?=E6=9B=B4=E5=8A=A0=E7=AE=80=E6=B4=81=E7=9A=84=E5=86=99=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0344.反转字符串.md | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/problems/0344.反转字符串.md b/problems/0344.反转字符串.md index 1b86e847..079ebb0b 100644 --- a/problems/0344.反转字符串.md +++ b/problems/0344.反转字符串.md @@ -157,7 +157,7 @@ class Solution { ``` Python： -```python3 +```python class Solution: def reverseString(self, s: List[str]) -> None: """ @@ -168,6 +168,17 @@ class Solution: s[left], s[right] = s[right], s[left] left += 1 right -= 1 + +# 下面的写法更加简洁，但是都是同样的算法 +# class Solution: +# def reverseString(self, s: List[str]) -> None: +# """ +# Do not return anything, modify s in-place instead. +# """ + # 不需要判别是偶数个还是奇数个序列，因为奇数个的时候，中间那个不需要交换就可 +# for i in range(len(s)//2): +# s[i], s[len(s)-1-i] = s[len(s)-1-i], s[i] +# return s ``` Go： From a150c61f9db97521b2b758affe64e202d6a821d4 Mon Sep 17 00:00:00 2001 From: KailokFung Date: Wed, 23 Jun 2021 18:01:20 +0800 Subject: [PATCH 05/12] =?UTF-8?q?fix(0239):=20=E6=96=B0=E5=A2=9E=E4=B8=80?= =?UTF-8?q?=E7=A7=8Djava=E5=86=99=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0239.滑动窗口最大值.md | 35 ++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/problems/0239.滑动窗口最大值.md b/problems/0239.滑动窗口最大值.md index d108335b..ad54a940 100644 --- a/problems/0239.滑动窗口最大值.md +++ b/problems/0239.滑动窗口最大值.md @@ -208,6 +208,7 @@ public: Java： ```Java +//解法一 //自定义数组 class MyQueue { Deque deque = new LinkedList<>(); @@ -260,6 +261,40 @@ class Solution { return res; } } + +//解法二 +//利用双端队列手动实现单调队列 +/** + * 用一个单调队列来存储对应的下标，每当窗口滑动的时候，直接取队列的头部指针对应的值放入结果集即可 + * 单调队列类似 （tail -->） 3 --> 2 --> 1 --> 0 (--> head) (右边为头结点，元素存的是下标) + */ +class Solution { + public int[] maxSlidingWindow(int[] nums, int k) { + ArrayDeque deque = new ArrayDeque<>(); + int n = nums.length; + int[] res = new int[n - k + 1]; + int idx = 0; + for(int i = 0; i < n; i++) { + // 根据题意，i为nums下标，是要在[i - k + 1, k] 中选到最大值，只需要保证两点 + // 1.队列头结点需要在[i - k + 1, k]范围内，不符合则要弹出 + while(!deque.isEmpty() && deque.peek() < i - k + 1){ + deque.poll(); + } + // 2.既然是单调，就要保证每次放进去的数字要比末尾的都大，否则也弹出 + while(!deque.isEmpty() && nums[deque.peekLast()] < nums[i]) { + deque.pollLast(); + } + + deque.offer(i); + + // 因为单调，当i增长到符合第一个k范围的时候，每滑动一步都将队列头节点放入结果就行了 + if(i >= k - 1){ + res[idx++] = nums[deque.peek()]; + } + } + return res; + } +} ``` Python： From bf7597facfb1f993024ff932fabe6f0bf5198b31 Mon Sep 17 00:00:00 2001 From: kok-s0s <2694308562@qq.com> Date: Wed, 23 Jun 2021 21:49:11 +0800 Subject: [PATCH 06/12] =?UTF-8?q?=E6=8F=90=E4=BE=9BJavascript=E7=89=88?= =?UTF-8?q?=E6=9C=AC=E7=9A=84=E3=80=8A=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2?= =?UTF-8?q?=E6=95=B0=E7=9A=84=E6=9C=80=E8=BF=91=E5=85=AC=E5=85=B1=E7=A5=96?= =?UTF-8?q?=E5=85=88=E3=80=8B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...35.二叉搜索树的最近公共祖先.md | 55 +++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/problems/0235.二叉搜索树的最近公共祖先.md b/problems/0235.二叉搜索树的最近公共祖先.md index d78db42a..a893c191 100644 --- a/problems/0235.二叉搜索树的最近公共祖先.md +++ b/problems/0235.二叉搜索树的最近公共祖先.md @@ -314,7 +314,62 @@ func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode { ``` +JavaScript版本 +> 递归 +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val) { + * this.val = val; + * this.left = this.right = null; + * } + */ + +/** + * @param {TreeNode} root + * @param {TreeNode} p + * @param {TreeNode} q + * @return {TreeNode} + */ +var lowestCommonAncestor = function(root, p, q) { + if(root.val > p.val && root.val > q.val) + return lowestCommonAncestor(root.left, p , q); + else if(root.val < p.val && root.val < q.val) + return lowestCommonAncestor(root.right, p , q); + return root; +}; +``` + +> 迭代 + +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val) { + * this.val = val; + * this.left = this.right = null; + * } + */ + +/** + * @param {TreeNode} root + * @param {TreeNode} p + * @param {TreeNode} q + * @return {TreeNode} + */ +var lowestCommonAncestor = function(root, p, q) { + while(1) { + if(root.val > p.val && root.val > q.val) + root = root.left; + else if(root.val < p.val && root.val < q.val) + root = root.right; + else + break; + } + return root; +}; +``` ----------------------- From 826927e6ad0d54dcfd92ff634b7496525b4d2004 Mon Sep 17 00:00:00 2001 From: kok-s0s <2694308562@qq.com> Date: Wed, 23 Jun 2021 22:15:10 +0800 Subject: [PATCH 07/12] =?UTF-8?q?=E6=8F=90=E4=BE=9BJavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC=E7=9A=84=E3=80=8A=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2?= =?UTF-8?q?=E6=A0=91=E4=B8=AD=E7=9A=84=E6=8F=92=E5=85=A5=E6=93=8D=E4=BD=9C?= =?UTF-8?q?=E3=80=8B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0701.二叉搜索树中的插入操作.md | 33 +++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/problems/0701.二叉搜索树中的插入操作.md b/problems/0701.二叉搜索树中的插入操作.md index 6a8ba7fc..0f5b603a 100644 --- a/problems/0701.二叉搜索树中的插入操作.md +++ b/problems/0701.二叉搜索树中的插入操作.md @@ -286,6 +286,39 @@ func insertIntoBST(root *TreeNode, val int) *TreeNode { } ``` +JavaScript版本 + +> 有返回值的递归写法 + +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val, left, right) { + * this.val = (val===undefined ? 0 : val) + * this.left = (left===undefined ? null : left) + * this.right = (right===undefined ? null : right) + * } + */ +/** + * @param {TreeNode} root + * @param {number} val + * @return {TreeNode} + */ +var insertIntoBST = function (root, val) { + const setInOrder = (root, val) => { + if (root === null) { + let node = new TreeNode(val); + return node; + } + if (root.val > val) + root.left = setInOrder(root.left, val); + else if (root.val < val) + root.right = setInOrder(root.right, val); + return root; + } + return setInOrder(root, val); +}; +``` From 007813f33b731210fb75f65c6a1309dd47f7b9a1 Mon Sep 17 00:00:00 2001 From: liulei <718356979@qq.com> Date: Thu, 24 Jun 2021 08:40:16 +0800 Subject: [PATCH 08/12] =?UTF-8?q?=E6=9B=B4=E6=96=B0=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E8=BF=AD=E4=BB=A3=E9=81=8D=E5=8E=86=EF=BC=8C?= =?UTF-8?q?=E5=A2=9E=E5=8A=A0java=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/二叉树的迭代遍历.md | 75 +++++++++++++++++++++++++++- 1 file changed, 74 insertions(+), 1 deletion(-) diff --git a/problems/二叉树的迭代遍历.md b/problems/二叉树的迭代遍历.md index 8706dc47..30b921ff 100644 --- a/problems/二叉树的迭代遍历.md +++ b/problems/二叉树的迭代遍历.md @@ -155,9 +155,82 @@ public: ## 其他语言版本 - Java： +```java +// 前序遍历顺序：中-左-右，入栈顺序：中-右-左 +class Solution { + public List preorderTraversal(TreeNode root) { + List result = new ArrayList<>(); + if (root == null){ + return result; + } + Stack stack = new Stack<>(); + stack.push(root); + while (!stack.isEmpty()){ + TreeNode node = stack.pop(); + result.add(node.val); + if (node.right != null){ + stack.push(node.right); + } + if (node.left != null){ + stack.push(node.left); + } + } + return result; + } +} + +// 中序遍历顺序: 左-中-右 入栈顺序： 左-右 +class Solution { + public List inorderTraversal(TreeNode root) { + List result = new ArrayList<>(); + if (root == null){ + return result; + } + Stack stack = new Stack<>(); + TreeNode cur = root; + while (cur != null || !stack.isEmpty()){ + if (cur != null){ + stack.push(cur); + cur = cur.left; + }else{ + cur = stack.pop(); + result.add(cur.val); + cur = cur.right; + } + } + return result; + } +} + +// 后序遍历顺序 左-右-中 入栈顺序：中-左-右 出栈顺序：中-右-左， 最后翻转结果 +class Solution { + public List postorderTraversal(TreeNode root) { + List result = new ArrayList<>(); + if (root == null){ + return result; + } + Stack stack = new Stack<>(); + stack.push(root); + while (!stack.isEmpty()){ + TreeNode node = stack.pop(); + result.add(node.val); + if (node.left != null){ + stack.push(node.left); + } + if (node.right != null){ + stack.push(node.right); + } + } + Collections.reverse(result); + return result; + } +} +``` + + + Python： ```python3 From fc2dc45a198f9562fcbefdb399d71482c8c45cd8 Mon Sep 17 00:00:00 2001 From: NevS <1173325467@qq.com> Date: Thu, 24 Jun 2021 21:41:10 +0800 Subject: [PATCH 09/12] =?UTF-8?q?=E5=A2=9E=E5=8A=A0=200617.=E5=90=88?= =?UTF-8?q?=E5=B9=B6=E4=BA=8C=E5=8F=89=E6=A0=91=20go=E7=89=88=20=EF=BC=88?= =?UTF-8?q?=E5=A2=9E=E5=8A=A0=E5=89=8D=E5=BA=8F=E9=81=8D=E5=8E=86=E7=AE=80?= =?UTF-8?q?=E6=B4=81=E7=89=88=E8=A7=A3=E9=A2=98=EF=BC=89?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 增加前序遍历简洁版解题 --- problems/0617.合并二叉树.md | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/problems/0617.合并二叉树.md b/problems/0617.合并二叉树.md index 2ff093a3..f325df64 100644 --- a/problems/0617.合并二叉树.md +++ b/problems/0617.合并二叉树.md @@ -368,6 +368,20 @@ func mergeTrees(t1 *TreeNode, t2 *TreeNode) *TreeNode { Right: mergeTrees(t1.Right,t2.Right)} return root } + +// 前序遍历简洁版 +func mergeTrees(root1 *TreeNode, root2 *TreeNode) *TreeNode { + if root1 == nil { + return root2 + } + if root2 == nil { + return root1 + } + root1.Val += root2.Val + root1.Left = mergeTrees(root1.Left, root2.Left) + root1.Right = mergeTrees(root1.Right, root2.Right) + return root1 +} ``` JavaScript: From 24e7994d2708b90f304dd424f0175bcce845955f Mon Sep 17 00:00:00 2001 From: Jijie LIU Date: Thu, 24 Jun 2021 20:29:02 +0200 Subject: [PATCH 10/12] =?UTF-8?q?update=2063.=20=E4=B8=8D=E5=90=8C?= =?UTF-8?q?=E8=B7=AF=E5=BE=84=20II=EF=BC=9A=E6=8F=90=E4=BE=9B=E4=B8=80?= =?UTF-8?q?=E7=BB=B4dp=E6=95=B0=E7=BB=84=E7=9A=84Python=E8=A7=A3=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0063.不同路径II.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0063.不同路径II.md b/problems/0063.不同路径II.md index 52f00322..a61ffd02 100644 --- a/problems/0063.不同路径II.md +++ b/problems/0063.不同路径II.md @@ -232,6 +232,38 @@ class Solution: return dp[-1][-1] ``` +```python +class Solution: + """ + 使用一维dp数组 + """ + + def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int: + m, n = len(obstacleGrid), len(obstacleGrid[0]) + + # 初始化dp数组 + # 该数组缓存当前行 + curr = [0] * n + for j in range(n): + if obstacleGrid[0][j] == 1: + break + curr[j] = 1 + + for i in range(1, m): # 从第二行开始 + for j in range(n): # 从第一列开始，因为第一列可能有障碍物 + # 有障碍物处无法通行，状态就设成0 + if obstacleGrid[i][j] == 1: + curr[j] = 0 + elif j > 0: + # 等价于 + # dp[i][j] = dp[i - 1][j] + dp[i][j - 1] + curr[j] = curr[j] + curr[j - 1] + # 隐含的状态更新 + # dp[i][0] = dp[i - 1][0] + + return curr[n - 1] +``` + Go： From ad1faf8a150a8954661e39cbd25f0fdc1b1f8b5b Mon Sep 17 00:00:00 2001 From: kok-s0s <2694308562@qq.com> Date: Fri, 25 Jun 2021 22:54:40 +0800 Subject: [PATCH 11/12] =?UTF-8?q?=E6=8F=90=E4=BE=9BJavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC=E7=9A=84=E3=80=8A=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2?= =?UTF-8?q?=E6=A0=91=E4=B8=AD=E7=9A=84=E6=8F=92=E5=85=A5=E6=93=8D=E4=BD=9C?= =?UTF-8?q?=E3=80=8B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0701.二叉搜索树中的插入操作.md | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) diff --git a/problems/0701.二叉搜索树中的插入操作.md b/problems/0701.二叉搜索树中的插入操作.md index 0f5b603a..794e0ae2 100644 --- a/problems/0701.二叉搜索树中的插入操作.md +++ b/problems/0701.二叉搜索树中的插入操作.md @@ -320,7 +320,84 @@ var insertIntoBST = function (root, val) { }; ``` +> 无返回值的递归 +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val, left, right) { + * this.val = (val===undefined ? 0 : val) + * this.left = (left===undefined ? null : left) + * this.right = (right===undefined ? null : right) + * } + */ +/** + * @param {TreeNode} root + * @param {number} val + * @return {TreeNode} + */ +var insertIntoBST = function (root, val) { + let parent = new TreeNode(0); + const preOrder = (cur, val) => { + if (cur === null) { + let node = new TreeNode(val); + if (parent.val > val) + parent.left = node; + else + parent.right = node; + return; + } + parent = cur; + if (cur.val > val) + preOrder(cur.left, val); + if (cur.val < val) + preOrder(cur.right, val); + } + if (root === null) + root = new TreeNode(val); + preOrder(root, val); + return root; +}; +``` + +> 迭代 + +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val, left, right) { + * this.val = (val===undefined ? 0 : val) + * this.left = (left===undefined ? null : left) + * this.right = (right===undefined ? null : right) + * } + */ +/** + * @param {TreeNode} root + * @param {number} val + * @return {TreeNode} + */ +var insertIntoBST = function (root, val) { + if (root === null) { + root = new TreeNode(val); + } else { + let parent = new TreeNode(0); + let cur = root; + while (cur) { + parent = cur; + if (cur.val > val) + cur = cur.left; + else + cur = cur.right; + } + let node = new TreeNode(val); + if (parent.val > val) + parent.left = node; + else + parent.right = node; + } + return root; +}; +``` ----------------------- * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) From b461cf71587352d713a61e5a5d3f56d72a100019 Mon Sep 17 00:00:00 2001 From: kok-s0s <2694308562@qq.com> Date: Fri, 25 Jun 2021 22:56:08 +0800 Subject: [PATCH 12/12] =?UTF-8?q?=E6=8F=90=E4=BE=9BJavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC=E7=9A=84=E3=80=8A=E5=88=A0=E9=99=A4=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=90=9C=E7=B4=A2=E6=A0=91=E4=B8=AD=E7=9A=84=E8=8A=82=E7=82=B9?= =?UTF-8?q?=E3=80=8B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../0450.删除二叉搜索树中的节点.md | 45 +++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/problems/0450.删除二叉搜索树中的节点.md b/problems/0450.删除二叉搜索树中的节点.md index 3ed44c0a..1cd3d370 100644 --- a/problems/0450.删除二叉搜索树中的节点.md +++ b/problems/0450.删除二叉搜索树中的节点.md @@ -359,6 +359,51 @@ func deleteNode1(root *TreeNode)*TreeNode{ } ``` +JavaScript版本 + +> 递归 + +```javascript +/** + * Definition for a binary tree node. + * function TreeNode(val, left, right) { + * this.val = (val===undefined ? 0 : val) + * this.left = (left===undefined ? null : left) + * this.right = (right===undefined ? null : right) + * } + */ +/** + * @param {TreeNode} root + * @param {number} key + * @return {TreeNode} + */ +var deleteNode = function (root, key) { + if (root === null) + return root; + if (root.val === key) { + if (!root.left) + return root.right; + else if (!root.right) + return root.left; + else { + let cur = root.right; + while (cur.left) { + cur = cur.left; + } + cur.left = root.left; + let temp = root; + root = root.right; + delete root; + return root; + } + } + if (root.val > key) + root.left = deleteNode(root.left, key); + if (root.val < key) + root.right = deleteNode(root.right, key); + return root; +}; +```