add: 验证回文字符串 Ⅱ

.vscode/settings.json

@@ -1,6 +1,8 @@
 {
   "cSpell.words": [
+    "Gitpod",
     "LVIII",
+    "Prinme",
     "abcdefg",
     "cdefgab",
     "chuan",
@@ -15,6 +17,7 @@
     "powx",
     "pwwkew",
     "subarray",
+    "subarrays",
     "umghlrlose",
     "xuan",
     "zhong",

README.md

@@ -86,6 +86,11 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
   - LeetCode 13. 罗马数字转整数 <https://leetcode-cn.com/problems/roman-to-integer/>
   - LintCode 419. 罗马数字转整数 <https://www.lintcode.com/problem/roman-to-integer/description>
 
+- [验证回文字符串 Ⅱ](src/string/valid-palindrome-ii.js)
+
+  - LeetCode 680. 验证回文字符串 Ⅱ <https://leetcode-cn.com/problems/valid-palindrome-ii/>
+  - LintCode 891. 有效回文 II <https://www.lintcode.com/problem/valid-palindrome-ii/description>
+
 ## 数组/队列/集合/映射
 
 - [电话号码的字母组合](src/array/letter-combinations-of-a-phone-number.js)
@@ -293,6 +298,11 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
   - LeetCode 387. 字符串中的第一个唯一字符 <https://leetcode-cn.com/problems/first-unique-character-in-a-string/>
   - LintCode 209. 第一个只出现一次的字符 <https://www.lintcode.com/problem/first-unique-character-in-a-string/description>
 
+- [乘积最大子数组](src/array/maximum-product-subarray.js)
+
+  - LeetCode 152. 乘积最大子数组 <https://leetcode-cn.com/problems/maximum-product-subarray/>
+  - LintCode 191. 乘积最大子序列 <https://www.lintcode.com/problem/maximum-product-subarray/description>
+
 ## 栈
 
 - [最大矩阵](src/stack/maximal-rectangle.js)
@@ -333,17 +343,17 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
 - [回文数](src/math/palindrome-number.js)
 
   - LeetCode 9. 回文数 <https://leetcode-cn.com/problems/palindrome-number/>
-  - LintCode 491. 回文数 <https://www.lintcode.com/problem/palindrome-number/>
+  - LintCode 491. 回文数 <https://www.lintcode.com/problem/palindrome-number/description>
 
 - [Pow(x, n)](src/math/powx-n.js)
 
   - LeetCode 50. Pow(x, n) <https://leetcode-cn.com/problems/powx-n/>
-  - LintCode 428. x的n次幂 <https://www.lintcode.com/problem/powx-n/>
+  - LintCode 428. x的n次幂 <https://www.lintcode.com/problem/powx-n/description>
 
 - [和为K的子数组](src/math/subarray-sum-equals-k.js)
 
   - LeetCode 560. 和为K的子数组 <https://leetcode-cn.com/problems/subarray-sum-equals-k/>
-  - LintCode 838. 子数组和为K <https://www.lintcode.com/problem/subarray-sum-equals-k/>
+  - LintCode 838. 子数组和为K <https://www.lintcode.com/problem/subarray-sum-equals-k/description>
 
 ## 堆
 
@@ -362,7 +372,7 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
 - [验证二叉搜索树](src/tree/validate-binary-search-tree.js)
 
   - LeetCode 98. 验证二叉搜索树 <https://leetcode-cn.com/problems/validate-binary-search-tree/>
-  - LintCode 95. 验证二叉查找树 <https://www.lintcode.com/problem/validate-binary-search-tree/>
+  - LintCode 95. 验证二叉查找树 <https://www.lintcode.com/problem/validate-binary-search-tree/description>
 
 - [二叉树的最近公共祖先](src/tree/lowest-common-ancestor-of-a-binary-tree.js)
 
@@ -415,4 +425,12 @@ LeetCode 与 LintCode 解题记录。此为个人练习仓库，代码中对重
 - [K个一组翻转链表](src/list/reverse-nodes-in-k-group.js)
 
   - LeetCode 25. K 个一组翻转链表 <https://leetcode-cn.com/problems/reverse-nodes-in-k-group/>
-  - LintCode 450. K组翻转链表 <https://www.lintcode.com/problem/reverse-nodes-in-k-group/>
+  - LintCode 450. K组翻转链表 <https://www.lintcode.com/problem/reverse-nodes-in-k-group/description>
+
+## 图
+
+- [课程表](src/graphs/course-schedule-ii.js)
+
+  - LeetCode 210. 课程表 II <https://leetcode-cn.com/problems/course-schedule-ii/>
+  - LeetCode 207. 课程表 <https://leetcode-cn.com/problems/course-schedule/>
+  - LintCode 615. 课程表 <https://www.lintcode.com/problem/course-schedule/description>

src/array/maximum-product-subarray.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+export const maxProduct = function (nums) {
+  let res = nums[0]
+  let prevMin = nums[0]
+  let prevMax = nums[0]
+  let tmp1 = 0; let tmp2 = 0
+  for (let i = 1; i < nums.length; i++) {
+    tmp1 = prevMin * nums[i]
+    tmp2 = prevMax * nums[i]
+    prevMin = Math.min(tmp1, tmp2, nums[i])
+    prevMax = Math.max(tmp1, tmp2, nums[i])
+    res = Math.max(prevMax, res)
+  }
+  return res
+}

src/graphs/course-schedule-ii.js

@@ -0,0 +1,34 @@
+/**
+ * @param {number} numCourses
+ * @param {number[][]} prerequisites
+ * @return {number[]}
+ */
+export const findOrder = function (numCourses, prerequisites) {
+  const courses = Array(numCourses).fill(0) // 初始化 上课 需要先完成课程 的门数
+  const obj = {} // 记录受该课程 影响的其他课
+  prerequisites.forEach(item => {
+    const one = item[0]; const two = item[1] // one 要上的课, two 需先完成的课
+    courses[one]++ // 门数 + 1
+    obj[two] ? obj[two].push(one) : obj[two] = [one] // 存在就加, 不存在就新建
+  })
+  const res = []
+  const queue = [] // 队列
+  courses.forEach((t, i) => { // 往队列添加 无需先上 就可以 上 的课
+    if (t === 0) queue.push(i) // 因为是从0开始的, 所以索引也能代替 课的名称
+  })
+  while (queue.length) {
+    const cur = queue.shift() // 出队   表示该课已经上了
+    res.push(cur) // 把出队的放入 结果数组
+    const list = obj[cur] // 获取受该课影响的 课
+    list && list.forEach(item => {
+      courses[item]-- // 因为 出队表示该课已经上了, 所以 要先完成的门数 - 1
+      if (courses[item] === 0) { // 当这个课 要先修完的 已经修完了, 入队
+        queue.push(item)
+      }
+    })
+  }
+
+  return res.length === numCourses ? res : []
+}
+
+// 参考自 https://leetcode-cn.com/problems/course-schedule-ii/solution/chao-da-an-by-shetia/

src/string/valid-palindrome-ii.js

@@ -0,0 +1,37 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+export const validPalindrome = function (s, flag = true) {
+  let l = 0; let r = s.length - 1
+  while (l < r && s[l] === s[r]) {
+    l++; r--
+  }
+  if (l >= r) return true // 说明是回文
+  if (flag) return validPalindrome(s.slice(l, r), false) || validPalindrome(s.slice(l + 1, r + 1), false) // 如果不是回文，切左边或者右边，再判断一次
+  return false
+}
+
+// 暴力解法，会超时
+// /**
+//  * @param {string} s
+//  * @return {boolean}
+//  */
+// export const validPalindrome = function (s) {
+//   const len = s.length
+//   const tmpLen = len - 1
+//   let mid = len >> 1
+//   if (s.substring(0, mid) === s.substring(len % 2 ? mid + 1 : mid, len).split('').reverse().join('')) {
+//     return true
+//   }
+
+//   mid = tmpLen >> 1
+//   for (let n = 0; n < len; n++) {
+//     const tmp = s.substring(0, n) + s.substring(n + 1, len)
+//     if (tmp.substring(0, mid) === tmp.substring(tmpLen % 2 ? mid + 1 : mid, tmpLen).split('').reverse().join('')) {
+//       return true
+//     }
+//   }
+
+//   return false
+// }

test/array/maximum-product-subarray.test.js

@@ -0,0 +1,6 @@
+import { maxProduct } from '../../src/array/maximum-product-subarray'
+
+test('', () => {
+  expect(maxProduct([2, 3, -2, 4])).toBe(6)
+  expect(maxProduct([-2, 0, -1])).toBe(0)
+})

test/graphs/course-schedule-ii.test.js

@@ -0,0 +1,6 @@
+import { findOrder } from '../../src/graphs/course-schedule-ii'
+
+test('课程表 II', () => {
+  expect(findOrder(2, [[1, 0]])).toEqual([0, 1])
+  expect(findOrder(4, [[1, 0], [2, 0], [3, 1], [3, 2]])).toEqual([0, 1, 2, 3])
+})

test/string/valid-palindrome-ii.test.js

@@ -0,0 +1,8 @@
+import { validPalindrome } from '../../src/string/valid-palindrome-ii'
+
+test('验证回文字符串 Ⅱ', () => {
+  expect(validPalindrome('aba')).toBe(true)
+  expect(validPalindrome('abba')).toBe(true)
+  expect(validPalindrome('abca')).toBe(true)
+  expect(validPalindrome('abcda')).toBe(false)
+})