From 4f96f64e3d6f54eac978bdea355c22060f80d1ee Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Tue, 18 May 2021 15:59:48 +0200 Subject: [PATCH 01/10] =?UTF-8?q?Update=200530.=E4=BA=8C=E5=8F=89=E6=90=9C?= =?UTF-8?q?=E7=B4=A2=E6=A0=91=E7=9A=84=E6=9C=80=E5=B0=8F=E7=BB=9D=E5=AF=B9?= =?UTF-8?q?=E5=B7=AE.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit added python version of code --- .../0530.二叉搜索树的最小绝对差.md | 27 ++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/problems/0530.二叉搜索树的最小绝对差.md b/problems/0530.二叉搜索树的最小绝对差.md index 903ebf78..347d66d1 100644 --- a/problems/0530.二叉搜索树的最小绝对差.md +++ b/problems/0530.二叉搜索树的最小绝对差.md @@ -177,8 +177,29 @@ class Solution { ``` Python： - - +```python +# Definition for a binary tree node. +# class TreeNode: +# def __init__(self, val=0, left=None, right=None): +# self.val = val +# self.left = left +# self.right = right +class Solution: + def getMinimumDifference(self, root: TreeNode) -> int: + res = [] + r = float("inf") + def buildaList(root): //把二叉搜索树转换成有序数组 + if not root: return None + if root.left: buildaList(root.left) //左 + res.append(root.val) //中 + if root.right: buildaList(root.right) //右 + return res + + buildaList(root) + for i in range(len(res)-1): // 统计有序数组的最小差值 + r = min(abs(res[i]-res[i+1]),r) + return r +``` Go： @@ -188,4 +209,4 @@ Go： * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) * B站视频：[代码随想录](https://space.bilibili.com/525438321) * 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ) -
\ No newline at end of file +
From 41272638670e6da93171dfce8af63d5da42d4e36 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Tue, 18 May 2021 22:51:51 +0800 Subject: [PATCH 02/10] =?UTF-8?q?=E6=B7=BB=E5=8A=A0111.=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E6=9C=80=E5=B0=8F=E6=B7=B1=E5=BA=A6=20JavaSc?= =?UTF-8?q?ript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0111.二叉树的最小深度.md | 47 +++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/problems/0111.二叉树的最小深度.md b/problems/0111.二叉树的最小深度.md index 01b6c89c..5605e13d 100644 --- a/problems/0111.二叉树的最小深度.md +++ b/problems/0111.二叉树的最小深度.md @@ -302,6 +302,53 @@ class Solution: Go： +JavaScript: + +递归法： + +```javascript +/** + * @param {TreeNode} root + * @return {number} + */ +var minDepth1 = function(root) { + if(!root) return 0; + // 到叶子节点 返回 1 + if(!root.left && !root.right) return 1; + // 只有右节点时 递归右节点 + if(!root.left) return 1 + minDepth(root.right);、 + // 只有左节点时 递归左节点 + if(!root.right) return 1 + minDepth(root.left); + return Math.min(minDepth(root.left), minDepth(root.right)) + 1; +}; +``` + +迭代法： + +```javascript +/** +* @param {TreeNode} root +* @return {number} +*/ +var minDepth = function(root) { + if(!root) return 0; + const queue = [root]; + let dep = 0; + while(true) { + let size = queue.length; + dep++; + while(size--){ + const node = queue.shift(); + // 到第一个叶子节点 返回 当前深度 + if(!node.left && !node.right) return dep; + node.left && queue.push(node.left); + node.right && queue.push(node.right); + } + } +}; +``` + + ----------------------- From cf6ec4f65a8ee43a15c29f0a380cfac5f809a8dd Mon Sep 17 00:00:00 2001 From: X-shuffle <53906918+X-shuffle@users.noreply.github.com> Date: Tue, 18 May 2021 22:58:00 +0800 Subject: [PATCH 03/10] =?UTF-8?q?Update=20=E4=BA=8C=E5=8F=89=E6=A0=91?= =?UTF-8?q?=E7=9A=84=E8=BF=AD=E4=BB=A3=E9=81=8D=E5=8E=86.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 二叉树的迭代遍历 GO版本 --- problems/二叉树的迭代遍历.md | 102 +++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) 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 2647616b..d228077b 100644 --- a/problems/二叉树的迭代遍历.md +++ b/problems/二叉树的迭代遍历.md @@ -163,7 +163,109 @@ Python： Go： +> 迭代法前序遍历 +```go +//迭代法前序遍历 +/** + type Element struct { + // 元素保管的值 + Value interface{} + // 内含隐藏或非导出字段 +} + +func (l *List) Back() *Element +前序遍历：中左右 +压栈顺序：右左中 + **/ +func preorderTraversal(root *TreeNode) []int { + if root == nil { + return nil + } + var stack = list.New() + stack.PushBack(root.Right) + stack.PushBack(root.Left) + res:=[]int{} + res=append(res,root.Val) + for stack.Len()>0 { + e:=stack.Back() + stack.Remove(e) + node := e.Value.(*TreeNode)//e是Element类型，其值为e.Value.由于Value为接口，所以要断言 + if node==nil{ + continue + } + res=append(res,node.Val) + stack.PushBack(node.Right) + stack.PushBack(node.Left) + } + return res +} +``` + +> 迭代法后序遍历 + +```go +//后续遍历：左右中 +//压栈顺序：中右左(按照前序遍历思路)，再反转结果数组 +func postorderTraversal(root *TreeNode) []int { + if root == nil { + return nil + } + var stack = list.New() + stack.PushBack(root.Left) + stack.PushBack(root.Right) + res:=[]int{} + res=append(res,root.Val) + for stack.Len()>0 { + e:=stack.Back() + stack.Remove(e) + node := e.Value.(*TreeNode)//e是Element类型，其值为e.Value.由于Value为接口，所以要断言 + if node==nil{ + continue + } + res=append(res,node.Val) + stack.PushBack(node.Left) + stack.PushBack(node.Right) + } + for i:=0;i 迭代法中序遍历 + +```go +//迭代法中序遍历 +func inorderTraversal(root *TreeNode) []int { + rootRes:=[]int{} + if root==nil{ + return nil + } + stack:=list.New() + node:=root + //先将所有左节点找到，加入栈中 + for node!=nil{ + stack.PushBack(node) + node=node.Left + } + //其次对栈中的每个节点先弹出加入到结果集中，再找到该节点的右节点的所有左节点加入栈中 + for stack.Len()>0{ + e:=stack.Back() + node:=e.Value.(*TreeNode) + stack.Remove(e) + //找到该节点的右节点，再搜索他的所有左节点加入栈中 + rootRes=append(rootRes,node.Val) + node=node.Right + for node!=nil{ + stack.PushBack(node) + node=node.Left + } + } + return rootRes +} +``` From 1fcb8402232e4db9fb1af3312232f7c2e3f26ee5 Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Tue, 18 May 2021 15:45:10 -0400 Subject: [PATCH 04/10] =?UTF-8?q?Update=200454.=E5=9B=9B=E6=95=B0=E7=9B=B8?= =?UTF-8?q?=E5=8A=A0II.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0454.四数相加II.md | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/problems/0454.四数相加II.md b/problems/0454.四数相加II.md index a2ef928b..ad928a3f 100644 --- a/problems/0454.四数相加II.md +++ b/problems/0454.四数相加II.md @@ -121,6 +121,37 @@ class Solution { Python： +``` +class Solution(object): + def fourSumCount(self, nums1, nums2, nums3, nums4): + """ + :type nums1: List[int] + :type nums2: List[int] + :type nums3: List[int] + :type nums4: List[int] + :rtype: int + """ + # use a dict to store the elements in nums1 and nums2 and their sum + hashmap = dict() + for n1 in nums1: + for n2 in nums2: + if n1 + n2 in hashmap: + hashmap[n1+n2] += 1 + else: + hashmap[n1+n2] = 1 + + # if the -(a+b) exists in nums3 and nums4, we shall add the count + count = 0 + for n3 in nums3: + for n4 in nums4: + key = - n3 - n4 + if key in hashmap: + count += hashmap[key] + return count + + +``` + Go： From 830381313abb85357f180f6315e0e1c28c63c01d Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Tue, 18 May 2021 15:53:09 -0400 Subject: [PATCH 05/10] =?UTF-8?q?Update=200383.=E8=B5=8E=E9=87=91=E4=BF=A1?= =?UTF-8?q?.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0383.赎金信.md | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md index 2f7ae4d8..527945fa 100644 --- a/problems/0383.赎金信.md +++ b/problems/0383.赎金信.md @@ -136,7 +136,34 @@ class Solution { ``` Python： - +``` +class Solution(object): + def canConstruct(self, ransomNote, magazine): + """ + :type ransomNote: str + :type magazine: str + :rtype: bool + """ + + # use a dict to store the number of letter occurance in ransomNote + hashmap = dict() + for s in ransomNote: + if s in hashmap: + hashmap[s] += 1 + else: + hashmap[s] = 1 + + # check if the letter we need can be found in magazine + for l in magazine: + if l in hashmap: + hashmap[l] -= 1 + + for key in hashmap: + if hashmap[key] > 0: + return False + + return True +``` Go： From 9edc7aa01df2f652a170435870747a0896b0d83e Mon Sep 17 00:00:00 2001 From: charon2121 <66763177+charon2121@users.noreply.github.com> Date: Wed, 19 May 2021 08:28:50 +0800 Subject: [PATCH 06/10] =?UTF-8?q?=E6=9B=B4=E6=96=B0=20144.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E5=89=8D=E5=BA=8F=E9=81=8D=E5=8E=86?= =?UTF-8?q?=20python3=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 更新 145.二叉树的后序遍历 python3版本 更新 94.二叉树的中序遍历 python3版本 --- problems/二叉树的迭代遍历.md | 62 ++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) 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 2647616b..be2456de 100644 --- a/problems/二叉树的迭代遍历.md +++ b/problems/二叉树的迭代遍历.md @@ -160,6 +160,68 @@ Java： Python： +```python3 +# 前序遍历-迭代-LC144_二叉树的前序遍历 +class Solution: + def preorderTraversal(self, root: TreeNode) -> List[int]: + # 根结点为空则返回空列表 + if not root: + return [] + stack = [root] + result = [] + while stack: + node = stack.pop() + # 中结点先处理 + result.append(node.val) + # 右孩子先入栈 + if node.right: + stack.append(node.right) + # 左孩子后入栈 + if node.left: + stack.append(node.left) + return result + +# 中序遍历-迭代-LC94_二叉树的中序遍历 +class Solution: + def inorderTraversal(self, root: TreeNode) -> List[int]: + if not root: + return [] + stack = [] # 不能提前将root结点加入stack中 + result = [] + cur = root + while cur or stack: + # 先迭代访问最底层的左子树结点 + if cur: + stack.append(cur) + cur = cur.left + # 到达最左结点后处理栈顶结点 + else: + cur = stack.pop() + result.append(cur.val) + # 取栈顶元素右结点 + cur = cur.right + return result + +# 后序遍历-迭代-LC145_二叉树的后序遍历 +class Solution: + def postorderTraversal(self, root: TreeNode) -> List[int]: + if not root: + return [] + stack = [root] + result = [] + while stack: + node = stack.pop() + # 中结点先处理 + result.append(node.val) + # 左孩子先入栈 + if node.left: + stack.append(node.left) + # 右孩子后入栈 + if node.right: + stack.append(node.right) + # 将最终的数组翻转 + return result[::-1] +``` Go： From 44c8ce6a4f54869008961c62d2728548b6f24e04 Mon Sep 17 00:00:00 2001 From: X-shuffle <53906918+X-shuffle@users.noreply.github.com> Date: Wed, 19 May 2021 10:03:09 +0800 Subject: [PATCH 07/10] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20=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=20GO?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 二叉树的迭代遍历 GO版本 --- problems/二叉树的迭代遍历.md | 1 - 1 file changed, 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 d228077b..10e7e7b4 100644 --- a/problems/二叉树的迭代遍历.md +++ b/problems/二叉树的迭代遍历.md @@ -268,7 +268,6 @@ func inorderTraversal(root *TreeNode) []int { ``` - ----------------------- * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) * B站视频：[代码随想录](https://space.bilibili.com/525438321) From a57b6385c4ceccb7900cb9dc41a7eb3d6a59d2e5 Mon Sep 17 00:00:00 2001 From: X-shuffle <53906918+X-shuffle@users.noreply.github.com> Date: Wed, 19 May 2021 10:07:22 +0800 Subject: [PATCH 08/10] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20=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=20GO?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 二叉树的迭代遍历 GO版本 --- problems/二叉树的迭代遍历.md | 1 + 1 file changed, 1 insertion(+) 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 10e7e7b4..a1906469 100644 --- a/problems/二叉树的迭代遍历.md +++ b/problems/二叉树的迭代遍历.md @@ -205,6 +205,7 @@ func preorderTraversal(root *TreeNode) []int { > 迭代法后序遍历 ```go +//迭代法后序遍历 //后续遍历：左右中 //压栈顺序：中右左(按照前序遍历思路)，再反转结果数组 func postorderTraversal(root *TreeNode) []int { From c628620ceddbdbe236b1cbb6cc597431642ae260 Mon Sep 17 00:00:00 2001 From: QuinnDK <39618652+QuinnDK@users.noreply.github.com> Date: Wed, 19 May 2021 10:07:40 +0800 Subject: [PATCH 09/10] =?UTF-8?q?Update=200516.=E6=9C=80=E9=95=BF=E5=9B=9E?= =?UTF-8?q?=E6=96=87=E5=AD=90=E5=BA=8F=E5=88=97.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0516.最长回文子序列.md | 27 ++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/problems/0516.最长回文子序列.md b/problems/0516.最长回文子序列.md index d7acef99..7736b69f 100644 --- a/problems/0516.最长回文子序列.md +++ b/problems/0516.最长回文子序列.md @@ -173,6 +173,33 @@ Python： Go： +```Go +func longestPalindromeSubseq(s string) int { + lenth:=len(s) + dp:=make([][]int,lenth) + for i:=0;i=0;i--{ + for j:=i+1;j Date: Wed, 19 May 2021 10:25:58 +0800 Subject: [PATCH 10/10] =?UTF-8?q?Update=200055.=E8=B7=B3=E8=B7=83=E6=B8=B8?= =?UTF-8?q?=E6=88=8F.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0055.跳跃游戏.md | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/problems/0055.跳跃游戏.md b/problems/0055.跳跃游戏.md index a25c831a..ae2cbd1e 100644 --- a/problems/0055.跳跃游戏.md +++ b/problems/0055.跳跃游戏.md @@ -122,6 +122,24 @@ class Solution: ``` Go： +```Go +func canJUmp(nums []int) bool { + if len(nums)<=1{ + return true + } + dp:=make([]bool,len(nums)) + dp[0]=true + for i:=1;i=0;j--{ + if dp[j]&&nums[j]+j>=i{ + dp[i]=true + break + } + } + } + return dp[len(nums)-1] +} +```