From 961ae6eadf6359f2ef6b787ad612475e02e6842e Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 11 Feb 2022 21:52:36 +0800 Subject: [PATCH 1/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880112.=E8=B7=AF?= =?UTF-8?q?=E5=BE=84=E6=80=BB=E5=92=8C.md=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/0112.路径总和.md | 89 +++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/problems/0112.路径总和.md b/problems/0112.路径总和.md index 5ec8ffd0..de6caef0 100644 --- a/problems/0112.路径总和.md +++ b/problems/0112.路径总和.md @@ -766,11 +766,100 @@ let pathSum = function(root, targetSum) { }; ``` +## TypeScript + +> 0112.路径总和 + +**递归法:** + +```typescript +function hasPathSum(root: TreeNode | null, targetSum: number): boolean { + function recur(node: TreeNode, sum: number): boolean { + console.log(sum); + if ( + node.left === null && + node.right === null && + sum === 0 + ) return true; + if (node.left !== null) { + sum -= node.left.val; + if (recur(node.left, sum) === true) return true; + sum += node.left.val; + } + if (node.right !== null) { + sum -= node.right.val; + if (recur(node.right, sum) === true) return true; + sum += node.right.val; + } + return false; + } + if (root === null) return false; + return recur(root, targetSum - root.val); +}; +``` + +**递归法(精简版):** + +```typescript +function hasPathSum(root: TreeNode | null, targetSum: number): boolean { + if (root === null) return false; + targetSum -= root.val; + if ( + root.left === null && + root.right === null && + targetSum === 0 + ) return true; + return hasPathSum(root.left, targetSum) || + hasPathSum(root.right, targetSum); +}; +``` + +**迭代法:** + +```typescript +function hasPathSum(root: TreeNode | null, targetSum: number): boolean { + type Pair = { + node: TreeNode, // 当前节点 + sum: number // 根节点到当前节点的路径数值总和 + } + + const helperStack: Pair[] = []; + if (root !== null) helperStack.push({ node: root, sum: root.val }); + let tempPair: Pair; + while (helperStack.length > 0) { + tempPair = helperStack.pop()!; + if ( + tempPair.node.left === null && + tempPair.node.right === null && + tempPair.sum === targetSum + ) return true; + if (tempPair.node.right !== null) { + helperStack.push({ + node: tempPair.node.right, + sum: tempPair.sum + tempPair.node.right.val + }); + } + if (tempPair.node.left !== null) { + helperStack.push({ + node: tempPair.node.left, + sum: tempPair.sum + tempPair.node.left.val + }); + } + } + return false; +}; +``` + +> 0112.路径总和 ii + + + ## Swift 0112.路径总和 **递归** + ```swift func hasPathSum(_ root: TreeNode?, _ targetSum: Int) -> Bool { guard let root = root else { From fde074cb2ab400b44707c178139d7757541bbf39 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Fri, 11 Feb 2022 23:28:30 +0800 Subject: [PATCH 2/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880112.=E8=B7=AF?= =?UTF-8?q?=E5=BE=84=E6=80=BB=E5=92=8C=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/0112.路径总和.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0112.路径总和.md b/problems/0112.路径总和.md index de6caef0..2e10d98d 100644 --- a/problems/0112.路径总和.md +++ b/problems/0112.路径总和.md @@ -852,7 +852,39 @@ function hasPathSum(root: TreeNode | null, targetSum: number): boolean { > 0112.路径总和 ii +**递归法:** +```typescript +function pathSum(root: TreeNode | null, targetSum: number): number[][] { + function recur(node: TreeNode, sumGap: number, routeArr: number[]): void { + if ( + node.left === null && + node.right === null && + sumGap === 0 + ) resArr.push([...routeArr]); + if (node.left !== null) { + sumGap -= node.left.val; + routeArr.push(node.left.val); + recur(node.left, sumGap, routeArr); + sumGap += node.left.val; + routeArr.pop(); + } + if (node.right !== null) { + sumGap -= node.right.val; + routeArr.push(node.right.val); + recur(node.right, sumGap, routeArr); + sumGap += node.right.val; + routeArr.pop(); + } + } + const resArr: number[][] = []; + if (root === null) return resArr; + const routeArr: number[] = []; + routeArr.push(root.val); + recur(root, targetSum - root.val, routeArr); + return resArr; +}; +``` ## Swift