From 1efb77e96310d884eb2b8647232dd1586f4f0afb Mon Sep 17 00:00:00 2001 From: zucong Date: Tue, 25 Jan 2022 14:33:12 +0800 Subject: [PATCH 01/13] =?UTF-8?q?=E4=BC=98=E5=8C=96=200112.=E8=B7=AF?= =?UTF-8?q?=E5=BE=84=E6=80=BB=E5=92=8C=20Go=E7=89=88=E6=9C=AC=E8=A7=A3?= =?UTF-8?q?=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0112.路径总和.md | 101 ++++++++++++++-------------------- 1 file changed, 41 insertions(+), 60 deletions(-) diff --git a/problems/0112.路径总和.md b/problems/0112.路径总和.md index 910e57c8..b3e121ba 100644 --- a/problems/0112.路径总和.md +++ b/problems/0112.路径总和.md @@ -531,82 +531,63 @@ class solution: ```go //递归法 /** - * definition for a binary tree node. - * type treenode struct { - * val int - * left *treenode - * right *treenode + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode * } */ -func haspathsum(root *treenode, targetsum int) bool { - var flage bool //找没找到的标志 - if root==nil{ - return flage +func hasPathSum(root *TreeNode, targetSum int) bool { + if root == nil { + return false } - pathsum(root,0,targetsum,&flage) - return flage -} -func pathsum(root *treenode, sum int,targetsum int,flage *bool){ - sum+=root.val - if root.left==nil&&root.right==nil&&sum==targetsum{ - *flage=true - return - } - if root.left!=nil&&!(*flage){//左节点不为空且还没找到 - pathsum(root.left,sum,targetsum,flage) - } - if root.right!=nil&&!(*flage){//右节点不为空且没找到 - pathsum(root.right,sum,targetsum,flage) + + targetSum -= root.Val // 将targetSum在遍历每层的时候都减去本层节点的值 + if root.Left == nil && root.Right == nil && targetSum == 0 { // 如果剩余的targetSum为0, 则正好就是符合的结果 + return true } + return hasPathSum(root.Left, targetSum) || hasPathSum(root.Right, targetSum) // 否则递归找 } ``` -113 递归法 +113. 路径总和 II ```go /** - * definition for a binary tree node. - * type treenode struct { - * val int - * left *treenode - * right *treenode + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode * } */ -func pathsum(root *treenode, targetsum int) [][]int { - var result [][]int//最终结果 - if root==nil{ - return result - } - var sumnodes []int//经过路径的节点集合 - haspathsum(root,&sumnodes,targetsum,&result) +func pathSum(root *TreeNode, targetSum int) [][]int { + result := make([][]int, 0) + traverse(root, &result, new([]int), targetSum) return result } -func haspathsum(root *treenode,sumnodes *[]int,targetsum int,result *[][]int){ - *sumnodes=append(*sumnodes,root.val) - if root.left==nil&&root.right==nil{//叶子节点 - fmt.println(*sumnodes) - var sum int - var number int - for k,v:=range *sumnodes{//求该路径节点的和 - sum+=v - number=k - } - tempnodes:=make([]int,number+1)//新的nodes接受指针里的值，防止最终指针里的值发生变动，导致最后的结果都是最后一个sumnodes的值 - for k,v:=range *sumnodes{ - tempnodes[k]=v - } - if sum==targetsum{ - *result=append(*result,tempnodes) - } + +func traverse(node *TreeNode, result *[][]int, currPath *[]int, targetSum int) { + if node == nil { // 这个判空也可以挪到递归遍历左右子树时去判断 + return } - if root.left!=nil{ - haspathsum(root.left,sumnodes,targetsum,result) - *sumnodes=(*sumnodes)[:len(*sumnodes)-1]//回溯 - } - if root.right!=nil{ - haspathsum(root.right,sumnodes,targetsum,result) - *sumnodes=(*sumnodes)[:len(*sumnodes)-1]//回溯 + + targetSum -= node.Val // 将targetSum在遍历每层的时候都减去本层节点的值 + *currPath = append(*currPath, node.Val) // 把当前节点放到路径记录里 + + if node.Left == nil && node.Right == nil && targetSum == 0 { // 如果剩余的targetSum为0, 则正好就是符合的结果 + // 不能直接将currPath放到result里面, 因为currPath是共享的, 每次遍历子树时都会被修改 + pathCopy := make([]int, len(*currPath)) + for i, element := range *currPath { + pathCopy[i] = element + } + *result = append(*result, pathCopy) // 将副本放到结果集里 } + + traverse(node.Left, result, currPath, targetSum) + traverse(node.Right, result, currPath, targetSum) + *currPath = (*currPath)[:len(*currPath)-1] // 当前节点遍历完成, 从路径记录里删除掉 } ``` From 7ed2a3aef7b10b48fe7f8127f185f4a6efc9952c Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Wed, 26 Jan 2022 19:18:23 +0800 Subject: [PATCH 02/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E7=BB=9F=E4=B8=80=E8=BF=AD=E4=BB=A3?= =?UTF-8?q?=E6=B3=95.md=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/二叉树的统一迭代法.md | 68 +++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/problems/二叉树的统一迭代法.md b/problems/二叉树的统一迭代法.md index 2ff84817..f6edf586 100644 --- a/problems/二叉树的统一迭代法.md +++ b/problems/二叉树的统一迭代法.md @@ -522,7 +522,75 @@ var postorderTraversal = function(root, res = []) { ``` +TypeScript： +```typescript +// 前序遍历（迭代法） +function preorderTraversal(root: TreeNode | null): number[] { + let helperStack: (TreeNode | null)[] = []; + let res: number[] = []; + let curNode: TreeNode | null; + if (root === null) return res; + helperStack.push(root); + while (helperStack.length > 0) { + curNode = helperStack.pop()!; + if (curNode !== null) { + if (curNode.right !== null) helperStack.push(curNode.right); + helperStack.push(curNode); + helperStack.push(null); + if (curNode.left !== null) helperStack.push(curNode.left); + } else { + curNode = helperStack.pop()!; + res.push(curNode.val); + } + } + return res; +}; + +// 中序遍历（迭代法） +function inorderTraversal(root: TreeNode | null): number[] { + let helperStack: (TreeNode | null)[] = []; + let res: number[] = []; + let curNode: TreeNode | null; + if (root === null) return res; + helperStack.push(root); + while (helperStack.length > 0) { + curNode = helperStack.pop()!; + if (curNode !== null) { + if (curNode.right !== null) helperStack.push(curNode.right); + helperStack.push(curNode); + helperStack.push(null); + if (curNode.left !== null) helperStack.push(curNode.left); + } else { + curNode = helperStack.pop()!; + res.push(curNode.val); + } + } + return res; +}; + +// 后序遍历（迭代法） +function postorderTraversal(root: TreeNode | null): number[] { + let helperStack: (TreeNode | null)[] = []; + let res: number[] = []; + let curNode: TreeNode | null; + if (root === null) return res; + helperStack.push(root); + while (helperStack.length > 0) { + curNode = helperStack.pop()!; + if (curNode !== null) { + if (curNode.right !== null) helperStack.push(curNode.right); + helperStack.push(curNode); + helperStack.push(null); + if (curNode.left !== null) helperStack.push(curNode.left); + } else { + curNode = helperStack.pop()!; + res.push(curNode.val); + } + } + return res; +}; +``` -----------------------
From 878231551829fdd9deea2f2457eb09b794d7ed65 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Wed, 26 Jan 2022 21:20:36 +0800 Subject: [PATCH 03/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880102.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E5=B1=82=E5=BA=8F=E9=81=8D=E5=8E=86?= =?UTF-8?q?.md=20&=20107.=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84=E5=B1=82?= =?UTF-8?q?=E6=AC=A1=E9=81=8D=E5=8E=86=20II=EF=BC=89=EF=BC=9A=E5=A2=9E?= =?UTF-8?q?=E5=8A=A0typescript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 52 +++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 1fb9b633..b108c8f0 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -246,7 +246,35 @@ var levelOrder = function(root) { ``` +TypeScript： + +```typescript +function levelOrder(root: TreeNode | null): number[][] { + let helperQueue: TreeNode[] = []; + let res: number[][] = []; + let tempArr: number[] = []; + if (root !== null) helperQueue.push(root); + let curNode: TreeNode; + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + curNode = helperQueue.shift()!; + tempArr.push(curNode.val); + if (curNode.left !== null) { + helperQueue.push(curNode.left); + } + if (curNode.right !== null) { + helperQueue.push(curNode.right); + } + } + res.push(tempArr); + tempArr = []; + } + return res; +}; +``` + Swift: + ```swift func levelOrder(_ root: TreeNode?) -> [[Int]] { var res = [[Int]]() @@ -454,7 +482,31 @@ var levelOrderBottom = function(root) { }; ``` +TypeScript: + +```typescript +function levelOrderBottom(root: TreeNode | null): number[][] { + let helperQueue: TreeNode[] = []; + let resArr: number[][] = []; + let tempArr: number[] = []; + let tempNode: TreeNode; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + tempNode = helperQueue.shift()!; + tempArr.push(tempNode.val); + if (tempNode.left !== null) helperQueue.push(tempNode.left); + if (tempNode.right !== null) helperQueue.push(tempNode.right); + } + resArr.push(tempArr); + tempArr = []; + } + return resArr.reverse(); +}; +``` + Swift: + ```swift func levelOrderBottom(_ root: TreeNode?) -> [[Int]] { var res = [[Int]]() From e177bca526cd33ff4dce70b188f2214598941b0e Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Thu, 27 Jan 2022 22:35:30 +0800 Subject: [PATCH 04/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88199.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E5=8F=B3=E8=A7=86=E5=9B=BE=EF=BC=89?= =?UTF-8?q?=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index b108c8f0..18e19227 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -709,7 +709,28 @@ var rightSideView = function(root) { }; ``` +TypeScript： + +```typescript +function rightSideView(root: TreeNode | null): number[] { + let helperQueue: TreeNode[] = []; + let resArr: number[] = []; + let tempNode: TreeNode; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + tempNode = helperQueue.shift()!; + if (i === length - 1) resArr.push(tempNode.val); + if (tempNode.left !== null) helperQueue.push(tempNode.left); + if (tempNode.right !== null) helperQueue.push(tempNode.right); + } + } + return resArr; +}; +``` + Swift: + ```swift func rightSideView(_ root: TreeNode?) -> [Int] { var res = [Int]() From daf710bde6eb82f2c5b2a87254ca9860d79af80e Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 11:32:57 +0800 Subject: [PATCH 05/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88637.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E5=B1=82=E5=B9=B3=E5=9D=87=E5=80=BC?= =?UTF-8?q?=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 25 +++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 18e19227..9ff4f2e9 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -941,7 +941,32 @@ var averageOfLevels = function(root) { }; ``` +TypeScript： + +```typescript +function averageOfLevels(root: TreeNode | null): number[] { + let helperQueue: TreeNode[] = []; + let resArr: number[] = []; + let total: number = 0; + let tempNode: TreeNode; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + let length = helperQueue.length; + for (let i = 0; i < length; i++) { + tempNode = helperQueue.shift()!; + total += tempNode.val; + if (tempNode.left) helperQueue.push(tempNode.left); + if (tempNode.right) helperQueue.push(tempNode.right); + } + resArr.push(total / length); + total = 0; + } + return resArr; +}; +``` + Swift: + ```swift func averageOfLevels(_ root: TreeNode?) -> [Double] { var res = [Double]() From 2862d47368512a9cbc7e7184775d99d8e53f72df Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 11:44:49 +0800 Subject: [PATCH 06/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88429.N=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E5=B1=82=E5=BA=8F=E9=81=8D=E5=8E=86=EF=BC=89?= =?UTF-8?q?=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 9ff4f2e9..5dd448b7 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -1190,7 +1190,30 @@ var levelOrder = function(root) { }; ``` +TypeScript: + +```typescript +function levelOrder(root: Node | null): number[][] { + let helperQueue: Node[] = []; + let resArr: number[][] = []; + let tempArr: number[] = []; + if (root !== null) helperQueue.push(root); + let curNode: Node; + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + curNode = helperQueue.shift()!; + tempArr.push(curNode.val); + helperQueue.push(...curNode.children); + } + resArr.push(tempArr); + tempArr = []; + } + return resArr; +}; +``` + Swift: + ```swift func levelOrder(_ root: Node?) -> [[Int]] { var res = [[Int]]() From 9329ecff5e95e5bc1e8cb17fbba1135765fd3286 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 12:02:15 +0800 Subject: [PATCH 07/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88515.=E5=9C=A8?= =?UTF-8?q?=E6=AF=8F=E4=B8=AA=E6=A0=91=E8=A1=8C=E4=B8=AD=E6=89=BE=E6=9C=80?= =?UTF-8?q?=E5=A4=A7=E5=80=BC=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescrip?= =?UTF-8?q?t=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 27 +++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 5dd448b7..6f90cb75 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -1393,7 +1393,34 @@ var largestValues = function(root) { }; ``` +TypeScript: + +```typescript +function largestValues(root: TreeNode | null): number[] { + let helperQueue: TreeNode[] = []; + let resArr: number[] = []; + let tempNode: TreeNode; + let max: number = 0; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + tempNode = helperQueue.shift()!; + if (i === 0) { + max = tempNode.val; + } else { + max = max > tempNode.val ? max : tempNode.val; + } + if (tempNode.left) helperQueue.push(tempNode.left); + if (tempNode.right) helperQueue.push(tempNode.right); + } + resArr.push(max); + } + return resArr; +}; +``` + Swift: + ```swift func largestValues(_ root: TreeNode?) -> [Int] { var res = [Int]() From 992cd6d7f3bc2b0065bf8f3f3ff064a13c66dde3 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 16:10:56 +0800 Subject: [PATCH 08/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88116.=E5=A1=AB?= =?UTF-8?q?=E5=85=85=E6=AF=8F=E4=B8=AA=E8=8A=82=E7=82=B9=E7=9A=84=E4=B8=8B?= =?UTF-8?q?=E4=B8=80=E4=B8=AA=E5=8F=B3=E4=BE=A7=E8=8A=82=E7=82=B9=E6=8C=87?= =?UTF-8?q?=E9=92=88=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 25 +++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 6f90cb75..12f96469 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -1611,6 +1611,31 @@ var connect = function(root) { }; ``` +TypeScript: + +```typescript +function connect(root: Node | null): Node | null { + let helperQueue: Node[] = []; + let preNode: Node, curNode: Node; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + if (i === 0) { + preNode = helperQueue.shift()!; + } else { + curNode = helperQueue.shift()!; + preNode.next = curNode; + preNode = curNode; + } + if (preNode.left) helperQueue.push(preNode.left); + if (preNode.right) helperQueue.push(preNode.right); + } + preNode.next = null; + } + return root; +}; +``` + go: ```GO From d1abb0cbb4397a950479788497e3ec21adbcea22 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 16:21:25 +0800 Subject: [PATCH 09/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88117.=E5=A1=AB?= =?UTF-8?q?=E5=85=85=E6=AF=8F=E4=B8=AA=E8=8A=82=E7=82=B9=E7=9A=84=E4=B8=8B?= =?UTF-8?q?=E4=B8=80=E4=B8=AA=E5=8F=B3=E4=BE=A7=E8=8A=82=E7=82=B9=E6=8C=87?= =?UTF-8?q?=E9=92=88II=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 25 +++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 12f96469..a7716d92 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -1862,6 +1862,31 @@ var connect = function(root) { return root; }; ``` +TypeScript: + +```typescript +function connect(root: Node | null): Node | null { + let helperQueue: Node[] = []; + let preNode: Node, curNode: Node; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + for (let i = 0, length = helperQueue.length; i < length; i++) { + if (i === 0) { + preNode = helperQueue.shift()!; + } else { + curNode = helperQueue.shift()!; + preNode.next = curNode; + preNode = curNode; + } + if (preNode.left) helperQueue.push(preNode.left); + if (preNode.right) helperQueue.push(preNode.right); + } + preNode.next = null; + } + return root; +}; +``` + go: ```GO From bdb0954e32976832b9bd99dd2dcb2744d55e665b Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 17:11:11 +0800 Subject: [PATCH 10/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88104.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E6=9C=80=E5=A4=A7=E6=B7=B1=E5=BA=A6?= =?UTF-8?q?=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index a7716d92..9ac23fdf 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -2131,7 +2131,28 @@ var maxDepth = function(root) { }; ``` +TypeScript: + +```typescript +function maxDepth(root: TreeNode | null): number { + let helperQueue: TreeNode[] = []; + let resDepth: number = 0; + let tempNode: TreeNode; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + resDepth++; + for (let i = 0, length = helperQueue.length; i < length; i++) { + tempNode = helperQueue.shift()!; + if (tempNode.left) helperQueue.push(tempNode.left); + if (tempNode.right) helperQueue.push(tempNode.right); + } + } + return resDepth; +}; +``` + Swift: + ```swift func maxDepth(_ root: TreeNode?) -> Int { guard let root = root else { From 626db3fc67ba0a478f39331c4788bca15314a720 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 28 Jan 2022 20:33:04 +0800 Subject: [PATCH 11/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88111.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E6=9C=80=E5=B0=8F=E6=B7=B1=E5=BA=A6?= =?UTF-8?q?=EF=BC=89=EF=BC=9A=E5=A2=9E=E5=8A=A0typescript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 9ac23fdf..1a92d42f 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -2349,7 +2349,29 @@ var minDepth = function(root) { }; ``` +TypeScript: + +```typescript +function minDepth(root: TreeNode | null): number { + let helperQueue: TreeNode[] = []; + let resMin: number = 0; + let tempNode: TreeNode; + if (root !== null) helperQueue.push(root); + while (helperQueue.length > 0) { + resMin++; + for (let i = 0, length = helperQueue.length; i < length; i++) { + tempNode = helperQueue.shift()!; + if (tempNode.left === null && tempNode.right === null) return resMin; + if (tempNode.left !== null) helperQueue.push(tempNode.left); + if (tempNode.right !== null) helperQueue.push(tempNode.right); + } + } + return resMin; +}; +``` + Swift： + ```swift func minDepth(_ root: TreeNode?) -> Int { guard let root = root else { From 653d645dabd54c9b2d94afc27dc3cb308f82b519 Mon Sep 17 00:00:00 2001 From: Younglesszzz <571688981@qq.com> Date: Sat, 29 Jan 2022 13:29:28 +0800 Subject: [PATCH 12/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E4=BA=86=E4=BA=8C?= =?UTF-8?q?=E7=BB=B4=E6=95=B0=E7=BB=84=E7=89=88=E6=9C=AC=EF=BC=8C=E7=9B=B8?= =?UTF-8?q?=E6=AF=94=E4=BA=8E=E4=B8=80=E7=BB=B4=E5=A5=BD=E7=90=86=E8=A7=A3?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../1049.最后一块石头的重量II.md | 37 +++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/problems/1049.最后一块石头的重量II.md b/problems/1049.最后一块石头的重量II.md index d64e7e56..7b67b1ac 100644 --- a/problems/1049.最后一块石头的重量II.md +++ b/problems/1049.最后一块石头的重量II.md @@ -153,6 +153,8 @@ public: Java： + +一维数组版本 ```Java class Solution { public int lastStoneWeightII(int[] stones) { @@ -173,6 +175,41 @@ class Solution { return sum - 2 * dp[target]; } } +``` +二维数组版本（便于理解） +```Java +class Solution { + public int lastStoneWeightII(int[] stones) { + int sum = 0; + for (int s : stones) { + sum += s; + } + + int target = sum / 2; + //初始化，dp[i][j]为可以放0-i物品，背包容量为j的情况下背包中的最大价值 + int[][] dp = new int[stones.length][target + 1]; + //dp[i][0]默认初始化为0 + //dp[0][j]取决于stones[0] + for (int j = stones[0]; j <= target; j++) { + dp[0][j] = stones[0]; + } + + for (int i = 1; i < stones.length; i++) { + for (int j = 1; j <= target; j++) {//注意是等于 + if (j >= stones[i]) { + //不放:dp[i - 1][j] 放:dp[i - 1][j - stones[i]] + stones[i] + dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - stones[i]] + stones[i]); + } else { + dp[i][j] = dp[i - 1][j]; + } + } + } + + System.out.println(dp[stones.length - 1][target]); + return (sum - dp[stones.length - 1][target]) - dp[stones.length - 1][target]; + } +} + ``` Python： From b1c3d5c4f9db71676ebc44f9c41a10778dfea1c5 Mon Sep 17 00:00:00 2001 From: Younglesszzz <571688981@qq.com> Date: Sat, 29 Jan 2022 13:39:27 +0800 Subject: [PATCH 13/13] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E4=BA=86=E4=BA=8C?= =?UTF-8?q?=E7=BB=B4=E6=95=B0=E7=BB=84=E7=89=88=E6=9C=AC=EF=BC=8C=E7=9B=B8?= =?UTF-8?q?=E6=AF=94=E4=BA=8E=E4=B8=80=E7=BB=B4=E5=A5=BD=E7=90=86=E8=A7=A3?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0416.分割等和子集.md | 39 +++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/problems/0416.分割等和子集.md b/problems/0416.分割等和子集.md index 45b8b416..9da1f8d5 100644 --- a/problems/0416.分割等和子集.md +++ b/problems/0416.分割等和子集.md @@ -210,6 +210,45 @@ class Solution { } ``` +二维数组版本（易于理解）： +```Java +class Solution { + public boolean canPartition(int[] nums) { + int sum = 0; + for (int i = 0; i < nums.length; i++) { + sum += nums[i]; + } + + if (sum % 2 == 1) + return false; + int target = sum / 2; + + //dp[i][j]代表可装物品为0-i，背包容量为j的情况下，背包内容量的最大价值 + int[][] dp = new int[nums.length][target + 1]; + + //初始化,dp[0][j]的最大价值nums[0](if j > weight[i]) + //dp[i][0]均为0，不用初始化 + for (int j = nums[0]; j <= target; j++) { + dp[0][j] = nums[0]; + } + + //遍历物品，遍历背包 + //递推公式: + for (int i = 1; i < nums.length; i++) { + for (int j = 0; j <= target; j++) { + //背包容量可以容纳nums[i] + if (j >= nums[i]) { + dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - nums[i]] + nums[i]); + } else { + dp[i][j] = dp[i - 1][j]; + } + } + } + + return dp[nums.length - 1][target] == target; + } +} +``` Python： ```python class Solution: