From 1dcbf7f6f0ba7b50da6685532a42d2ceac9aeccc Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Sun, 3 Apr 2022 19:43:34 +0800 Subject: [PATCH 1/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=88=E5=9B=9E?= =?UTF-8?q?=E6=BA=AF=E7=AE=97=E6=B3=95=E5=8E=BB=E9=87=8D=E9=97=AE=E9=A2=98?= =?UTF-8?q?=E7=9A=84=E5=8F=A6=E4=B8=80=E7=A7=8D=E5=86=99=E6=B3=95.md?= =?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 --- ...溯算法去重问题的另一种写法.md | 81 +++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/problems/回溯算法去重问题的另一种写法.md b/problems/回溯算法去重问题的另一种写法.md index b4bdda00..f48097e1 100644 --- a/problems/回溯算法去重问题的另一种写法.md +++ b/problems/回溯算法去重问题的另一种写法.md @@ -365,6 +365,87 @@ class Solution: return res ``` +TypeScript： + +**90.子集II** + +```typescript +function subsetsWithDup(nums: number[]): number[][] { + nums.sort((a, b) => a - b); + const resArr: number[][] = []; + backTraking(nums, 0, []); + return resArr; + function backTraking(nums: number[], startIndex: number, route: number[]): void { + resArr.push(route.slice()); + const helperSet: Set = new Set(); + for (let i = startIndex, length = nums.length; i < length; i++) { + if (helperSet.has(nums[i])) continue; + helperSet.add(nums[i]); + route.push(nums[i]); + backTraking(nums, i + 1, route); + route.pop(); + } + } +}; +``` + +**40. 组合总和 II** + +```typescript +function combinationSum2(candidates: number[], target: number): number[][] { + candidates.sort((a, b) => a - b); + const resArr: number[][] = []; + backTracking(candidates, target, 0, 0, []); + return resArr; + function backTracking( + candidates: number[], target: number, + curSum: number, startIndex: number, route: number[] + ) { + if (curSum > target) return; + if (curSum === target) { + resArr.push(route.slice()); + return; + } + const helperSet: Set = new Set(); + for (let i = startIndex, length = candidates.length; i < length; i++) { + let tempVal: number = candidates[i]; + if (helperSet.has(tempVal)) continue; + helperSet.add(tempVal); + route.push(tempVal); + backTracking(candidates, target, curSum + tempVal, i + 1, route); + route.pop(); + + } + } +}; +``` + +**47. 全排列 II** + +```typescript +function permuteUnique(nums: number[]): number[][] { + const resArr: number[][] = []; + const usedArr: boolean[] = []; + backTracking(nums, []); + return resArr; + function backTracking(nums: number[], route: number[]): void { + if (nums.length === route.length) { + resArr.push(route.slice()); + return; + } + const usedSet: Set = new Set(); + for (let i = 0, length = nums.length; i < length; i++) { + if (usedArr[i] === true || usedSet.has(nums[i])) continue; + usedSet.add(nums[i]); + route.push(nums[i]); + usedArr[i] = true; + backTracking(nums, route); + usedArr[i] = false; + route.pop(); + } + } +}; +``` Go： From 3635751759fcf689f9baae10ab5fe4a5d642b5f8 Mon Sep 17 00:00:00 2001 From: Steve2020 <841532108@qq.com> Date: Sun, 3 Apr 2022 23:15:06 +0800 Subject: [PATCH 2/3] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=EF=BC=880332.=E9=87=8D?= =?UTF-8?q?=E6=96=B0=E5=AE=89=E6=8E=92=E8=A1=8C=E7=A8=8B.md=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/0332.重新安排行程.md | 44 +++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/problems/0332.重新安排行程.md b/problems/0332.重新安排行程.md index 01f81c4d..370db45b 100644 --- a/problems/0332.重新安排行程.md +++ b/problems/0332.重新安排行程.md @@ -448,6 +448,50 @@ var findItinerary = function(tickets) { ``` +### TypeScript + +```typescript +function findItinerary(tickets: string[][]): string[] { + /** + TicketsMap 实例： + { NRT: Map(1) { 'JFK' => 1 }, JFK: Map(2) { 'KUL' => 1, 'NRT' => 1 } } + 这里选择Map数据结构的原因是：与Object类型的一个主要差异是，Map实例会维护键值对的插入顺序。 + */ + type TicketsMap = { + [index: string]: Map + }; + tickets.sort((a, b) => { + return a[1] < b[1] ? -1 : 1; + }); + const ticketMap: TicketsMap = {}; + for (const [from, to] of tickets) { + if (ticketMap[from] === undefined) { + ticketMap[from] = new Map(); + } + ticketMap[from].set(to, (ticketMap[from].get(to) || 0) + 1); + } + const resRoute = ['JFK']; + backTracking(tickets.length, ticketMap, resRoute); + return resRoute; + function backTracking(ticketNum: number, ticketMap: TicketsMap, route: string[]): boolean { + if (route.length === ticketNum + 1) return true; + const targetMap = ticketMap[route[route.length - 1]]; + if (targetMap !== undefined) { + for (const [to, count] of targetMap.entries()) { + if (count > 0) { + route.push(to); + targetMap.set(to, count - 1); + if (backTracking(ticketNum, ticketMap, route) === true) return true; + targetMap.set(to, count); + route.pop(); + } + } + } + return false; + } +}; +``` + ### Swift 直接迭代tickets数组： From d3a69ff358793c6c4f6f7636935b545437404f21 Mon Sep 17 00:00:00 2001 From: Camille0512 Date: Mon, 4 Apr 2022 12:55:12 +0800 Subject: [PATCH 3/3] Add one more python code --- problems/0098.验证二叉搜索树.md | 23 ++++++++++++++++- problems/0101.对称二叉树.md | 35 -------------------------- 2 files changed, 22 insertions(+), 36 deletions(-) diff --git a/problems/0098.验证二叉搜索树.md b/problems/0098.验证二叉搜索树.md index 4ed29619..ff4335fc 100644 --- a/problems/0098.验证二叉搜索树.md +++ b/problems/0098.验证二叉搜索树.md @@ -408,7 +408,28 @@ class Solution: return True ``` -## Go +```python +# 遵循Carl的写法，只添加了节点判断的部分 +class Solution: + def isValidBST(self, root: TreeNode) -> bool: + # method 2 + que, pre = [], None + while root or que: + while root: + que.append(root) + root = root.left + root = que.pop() + # 对第一个节点只做记录，对后面的节点进行比较 + if pre is None: + pre = root.val + else: + if pre >= root.val: return False + pre = root.val + root = root.right + return True +``` + +## Go ```Go import "math" diff --git a/problems/0101.对称二叉树.md b/problems/0101.对称二叉树.md index 0007b4d4..e4e232c8 100644 --- a/problems/0101.对称二叉树.md +++ b/problems/0101.对称二叉树.md @@ -437,41 +437,6 @@ class Solution: return True ``` -层序遍历 - -```python -class Solution: - def isSymmetric(self, root: TreeNode) -> bool: - if not root: return True - que, cnt = [[root.left, root.right]], 1 - while que: - nodes, tmp, sign = que.pop(), [], False - for node in nodes: - if not node: - tmp.append(None) - tmp.append(None) - else: - if node.left: - tmp.append(node.left) - sign = True - else: - tmp.append(None) - if node.right: - tmp.append(node.right) - sign = True - else: - tmp.append(None) - p1, p2 = 0, len(nodes) - 1 - while p1 < p2: - if (not nodes[p1] and nodes[p2]) or (nodes[p1] and not nodes[p2]): return False - elif nodes[p1] and nodes[p2] and nodes[p1].val != nodes[p2].val: return False - p1 += 1 - p2 -= 1 - if sign: que.append(tmp) - cnt += 1 - return True -``` - ## Go ```go