Merge branch 'master' of https://github.com/sl1673495/leetcode-javasc…

…ript

动态规划/可获得的最大点数-1423.js

@@ -0,0 +1,45 @@
+// 力扣超时 卡在第26个用例
+let maxScore = function (cardPoints, k) {
+  let n = cardPoints.length
+
+  let prevTimeChunk = []
+  for (let i = 0; i < n; i++) {
+    for (let j = i; j < n; j++) {
+      if (!prevTimeChunk[i]) {
+        prevTimeChunk[i] = []
+      }
+      prevTimeChunk[i][j] = 0
+    }
+  }
+
+  let currentTimeChunk = []
+
+  for (let time = 1; time <= k; time++) {
+    for (let i = n - 1; i >= 0; i--) {
+      for (let j = i; j < n; j++) {
+        if (!currentTimeChunk[i]) {
+          currentTimeChunk[i] = []
+        }
+
+        // 只剩一个可选 有次数的情况下就选这一项 否则为0
+        if (i === j) {
+          currentTimeChunk[i][j] = time > 0 ? cardPoints[i] : 0
+        }
+
+        let pickHead = cardPoints[i]
+        let pickTail = cardPoints[j]
+
+        currentTimeChunk[i][j] = Math.max(
+          pickHead + (prevTimeChunk[i + 1] ? prevTimeChunk[i + 1][j] || 0 : 0),
+          pickTail + (prevTimeChunk[i][j - 1] || 0)
+        )
+      }
+    }
+    prevTimeChunk = currentTimeChunk
+    currentTimeChunk = []
+  }
+
+  return prevTimeChunk[0][n - 1]
+}
+
+console.log(maxScore([1,79,80,1,1,1,200,1], 3))

可被K整除的子数组.js

@@ -0,0 +1,32 @@
+/**
+ * 暴力解 超时了
+ * @param {number[]} A
+ * @param {number} K
+ * @return {number}
+ */
+var subarraysDivByK = function (A, K) {
+  let prevPrefix = []
+  let currentPrefix = []
+  let count = 0
+  for (let i = A.length - 1; i >= 0; i--) {
+    let num = A[i]
+    judge(num)
+    for (let prev of prevPrefix) {
+      let sum = prev + num
+      judge(sum)
+    }
+    prevPrefix = currentPrefix
+    currentPrefix = []
+  }
+
+  function judge(num) {
+    if (num % K === 0 || num === 0) {
+      count++
+    }
+    currentPrefix.push(num)
+  }
+
+  return count
+}
+
+console.log(subarraysDivByK([4, 5, 0, -2, -3, 1], 5))

工具/排序速度.js

@@ -1,6 +1,7 @@
 const glob = require("glob")
 const path = require("path")
 const swap = require("./交换")
+const random = require("./随机值")
 
 function sortTest(sortFns, source, desc) {
   console.log(desc)
@@ -14,7 +15,14 @@ function sortTest(sortFns, source, desc) {
     const copy = source.slice()
     const start = new Date().getTime()
 
-    fn(copy)
+    try {
+      fn(copy)
+    } catch (e) {
+      return (table[fn.sortName] = {
+        结果: "程序异常",
+        原因: e.message,
+      })
+    }
 
     const end = new Date().getTime()
     const time = end - start
@@ -36,7 +44,6 @@ function getRandomArray(count) {
   for (let i = 0; i < count; i++) {
     arr.push(Math.floor(i * Math.random() * 10))
   }
-
   return arr
 }
 
@@ -55,6 +62,14 @@ function getNearlyArray(count, swapTime) {
   return arr
 }
 
+function getRangedArray(count, min, max) {
+  const arr = []
+  for (let i = 0; i < count; i++) {
+    arr.push(random(min, max))
+  }
+  return arr
+}
+
 function isSorted(target, source) {
   return (
     target.toString() ===
@@ -71,4 +86,6 @@ glob("排序/*.js", (err, result) => {
     .map((p) => require(path.resolve(p)))
     .filter(Boolean)
   sortTest(sortFunctions, () => getRandomArray(10000), "普通数组排序")
+  sortTest(sortFunctions, () => getNearlyArray(10000), "近似数组排序")
+  sortTest(sortFunctions, () => getRangedArray(10000), "大量重复值元素排序")
 })

工具/随机值.js

@@ -0,0 +1,5 @@
+function random(low, high) {
+  return Math.round(Math.random() * (high - low)) + low
+}
+
+module.exports = random

排序/快速排序-三路.js

@@ -0,0 +1,51 @@
+const swap = require("../工具/交换")
+const random = require("../工具/随机值")
+
+/**
+ * 三路快速排序
+ * 将 arr[l...r] 分为 < v, === v, > v三部分
+ * 之后递归的对 < v, > v 两部分三路快排
+ * @param {number[]} arr
+ */
+function quickSort(arr) {
+  _quickSort(arr, 0, arr.length - 1)
+  return arr
+}
+
+/**
+ * 对 arr[l...r] 部分进行快速排序
+ * @param {number[]} arr
+ * @param {number} l 左边界
+ * @param {number} r 右边界
+ */
+function _quickSort(arr, l, r) {
+  if (l >= r) {
+    return
+  }
+  let [p, q] = partition(arr, l, r)
+  _quickSort(arr, l, p)
+  _quickSort(arr, q, r)
+}
+
+/**
+ * 对 arr[l...r] 部分进行快速排序
+ * @param {number[]} arr
+ * @param {number} l 左边界
+ * @param {number} r 右边界
+ * @returns {number} 返回索引值p，使得arr[l...p-1] < arr[p] < arr[p+1...r]
+ */
+function partition(arr, left, right) {
+  // 取一个基准值 取随机值
+  let rand = random(left, right)
+  swap(arr, left, rand)
+  let pivot = arr[left]
+
+  // 三路 注意看注释里的区间
+  let lt = left // arr[left + 1...lt] < v
+  let gt = right + 1 // arr[gt...r] > v
+  let index = left + 1 // arr[lt + 1...index] === v
+}
+
+quickSort.sortName = "快速排序（三路）"
+
+module.exports = quickSort

排序/快速排序-空间.js

@@ -0,0 +1,24 @@
+function quickSort(arr) {
+  if (arr.length === 1 || arr.length === 0) {
+    return arr
+  }
+  const left = []
+
+  const right = []
+  const ref = arr[0]
+
+  for (let i = 1; i < arr.length; i++) {
+    let num = arr[i]
+    if (num < ref) {
+      left.push(num)
+    } else {
+      right.push(num)
+    }
+  }
+
+  return [...quickSort(left), ref, ...quickSort(right)]
+}
+
+quickSort.sortName = "快速排序（空间版）"
+
+module.exports = quickSort

排序/快速排序.js

@@ -1,4 +1,5 @@
 const swap = require("../工具/交换")
+const random = require("../工具/随机值")
 
 /**
  *
@@ -32,7 +33,9 @@ function _quickSort(arr, l, r) {
  * @returns {number} 返回索引值p，使得arr[l...p-1] < arr[p] < arr[p+1...r]
  */
 function partition(arr, left, right) {
-  // 取一个基准值 取第一项
+  // 取一个基准值 取随机值
+  let rand = random(left, right)
+  swap(arr, left, rand)
   let pivot = arr[left]
 
   // arr[left+1...index] < pivot, arr[index+1...i) > pivot