feat: 快排空间

Author: sl1673495

可被K整除的子数组.js

@@ -11,23 +11,22 @@ var subarraysDivByK = function (A, K) {
   for (let i = A.length - 1; i >= 0; i--) {
     let num = A[i]
     judge(num)
-    currentPrefix.push(num)
     for (let prev of prevPrefix) {
       let sum = prev + num
       judge(sum)
-      currentPrefix.push(sum)
     }
     prevPrefix = currentPrefix
     currentPrefix = []
   }
 
-  return count
-
   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))
+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)
@@ -36,7 +37,6 @@ function getRandomArray(count) {
   for (let i = 0; i < count; i++) {
     arr.push(Math.floor(i * Math.random() * 10))
   }
-
   return arr
 }
 
@@ -55,6 +55,14 @@ 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() ===
@@ -71,5 +79,6 @@ 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(50000), "近似数组排序")
+  sortTest(sortFunctions, () => getNearlyArray(10000), "近似数组排序")
+  sortTest(sortFunctions, () => getRangedArray(10000), "大量重复值元素排序")
 })

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

@@ -33,7 +33,7 @@ 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]