feat(Go-Tool)：新增二分法查找算法及其单测、插入查询及其单测、lomuto划分查询第k小元素及其单测、归并排序及其单测、快速排序及其单测.

util/search/BinarySearch.go

@@ -0,0 +1,28 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/18 17:45
+ *  @Description：二分查找法，对于有序数组进行查找
+ */
+
+package search
+
+func BinarySearch(list []int, value int) int {
+	low := 0
+	high := len(list) - 1
+	var mid int
+
+	for low <= high {
+		mid = (low + high) >> 1 //相当于(low + high) / 2
+		if value == list[mid] {
+			return mid
+		}
+
+		if value < list[mid] {
+			high = mid - 1
+		} else {
+			low = mid + 1
+		}
+	}
+
+	return -1
+}

util/search/BinarySearch_test.go

@@ -0,0 +1,42 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/18 17:59
+ *  @Description：
+ */
+
+package search
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestBinarySearch(t *testing.T) {
+
+	evenNumList := []int{1, 2, 3, 5, 6, 7, 9, 10, 22, 111, 333, 431}
+
+	for _, r := range evenNumList {
+		position := BinarySearch(evenNumList, r)
+		fmt.Println(position)
+	}
+
+	position := BinarySearch(evenNumList, 999)
+	fmt.Println(position)
+
+	position = BinarySearch(evenNumList, -10)
+	fmt.Println(position)
+
+	fmt.Println()
+
+	oddNumList := []int{1, 2, 3, 5, 6, 7, 9, 10, 22, 111, 333, 431, 3211}
+	for _, r := range oddNumList {
+		position := BinarySearch(oddNumList, r)
+		fmt.Println(position)
+	}
+
+	position = BinarySearch(oddNumList, 999)
+	fmt.Println(position)
+
+	position = BinarySearch(oddNumList, -10)
+	fmt.Println(position)
+}

util/search/InsertionSearch.go

@@ -0,0 +1,34 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 10:24
+ *  @Description：
+ *
+ */
+
+package search
+
+func InsertionSearch(list []int, value int) int {
+	low := 0
+	high := len(list) - 1
+	var mid int
+
+	//插值查找这边如果数字和起始数字差别大的话,计算出来的下标会越界挺多的
+	if value > list[high-1] || value < list[0] {
+		return -1
+	}
+
+	for low < high {
+		mid = low + (high-low)*(value-list[low])/(list[high]-list[low])
+		if value == list[mid] {
+			return mid
+		}
+
+		if value < list[mid] {
+			high = mid - 1
+		} else {
+			low = mid + 1
+		}
+	}
+
+	return -1
+}

util/search/InsertionSearch.md

@@ -0,0 +1,7 @@
+从折半查找中可以看出，折半查找的查找效率还是不错的。可是为什么要折半呢？为什么不是四分之一、八分之一呢？打个比方，在牛津词典里要查找“apple”这个单词，会首先翻开字典的中间部分，然后继续折半吗？
+肯定不会，对于查找单词“apple”，我们肯定是下意识的往字典的最前部分翻去，而查找单词“zero”则相反，我们会下意识的往字典的最后部分翻去。
+所以在折半查找法的基础上进行改造就出现了插值查找法，也叫做按比例查找。所以插值查找与折半查找唯一不同的是在于mid的计算方式上，它的计算方式为：
+
+mid = low + (high - low) * (searchValue - data[low]) / (data[high] - data[low])
+
+插值查找的时间复杂度也是O(log2n)，但是对于数据集合较长，且关键字分布比较均匀的数据集合来说，插值查找的算法性能比折半查找要好，其它的则不适用。

util/search/InsertionSearch_test.go

@@ -0,0 +1,42 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 10:38
+ *  @Description：
+ */
+
+package search
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestInsertionSearch(t *testing.T) {
+
+	evenNumList := []int{1, 2, 3, 5, 6, 7, 9, 10, 22, 111, 333, 431}
+
+	for _, r := range evenNumList {
+		position := InsertionSearch(evenNumList, r)
+		fmt.Println(position)
+	}
+
+	position := InsertionSearch(evenNumList, 999)
+	fmt.Println(position)
+
+	position = InsertionSearch(evenNumList, -10)
+	fmt.Println(position)
+
+	fmt.Println()
+
+	oddNumList := []int{1, 2, 3, 5, 6, 7, 9, 10, 22, 111, 333, 431, 3211}
+	for _, r := range oddNumList {
+		position := InsertionSearch(oddNumList, r)
+		fmt.Println(position)
+	}
+
+	position = InsertionSearch(oddNumList, 999)
+	fmt.Println(position)
+
+	position = InsertionSearch(oddNumList, -10)
+	fmt.Println(position)
+}

util/search/LomutoPartition.go

@@ -11,7 +11,7 @@ package search
 //start : 开始比较的数字下标
 //end   ：结束比较的数字下标
 //作用说明：
-func partition(list []int, start int, end int) int {
+func LomutoPartition(list []int, start int, end int) int {
 	moveSubscript := start
 	compareValue := list[start]
 	for i := start + 1; i <= end; i++ {
@@ -27,13 +27,13 @@ func partition(list []int, start int, end int) int {
 func LomutoQuiteSelect(list []int, pointPosition int) int {
 	positionCheck(pointPosition, len(list)) //下标校验
 
-	nowPosition := partition(list, 0, len(list)-1)
+	nowPosition := LomutoPartition(list, 0, len(list)-1)
 	//循环进行lomuto划分处理,知道找到我们需要的那个位置的元素
 	for nowPosition != pointPosition-1 {
 		if nowPosition > pointPosition-1 {
-			nowPosition = partition(list, 0, nowPosition)
+			nowPosition = LomutoPartition(list, 0, nowPosition)
 		} else {
-			nowPosition = partition(list, nowPosition+1, len(list)-1)
+			nowPosition = LomutoPartition(list, nowPosition+1, len(list)-1)
 		}
 	}
 

util/search/LomutoPartition_test.go

@@ -13,13 +13,13 @@ import (
 
 func TestPartition(t *testing.T) {
 	list := []int{99, 1, 2, 3, 4, 100, 200, 90, 5}
-	s := partition(list, 0, 9-1)
+	s := LomutoPartition(list, 0, 9-1)
 	fmt.Println(fmt.Sprintf("当前第一个元素应该存在位置为：%d", s))
 	for _, r := range list {
 		fmt.Print(r, " ")
 	}
 
-	s = partition(list, 0, 9-1)
+	s = LomutoPartition(list, 0, 9-1)
 	fmt.Println(fmt.Sprintf("当前第一个元素应该存在位置为：%d", s))
 	for _, r := range list {
 		fmt.Print(r, " ")

util/sort/MergeSort.go

@@ -0,0 +1,54 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 11:44
+ *  @Description：这边提供一个递归的归并排序算法，非递归的理解成本比较高，并且还有多路归并排序，需要理解对应概念
+ *  最坏时间复杂度O(nlogn)   最好时间复杂度O(logn)   空间复杂度O(n)
+ */
+
+package sort
+
+func MergeSort(list []int) {
+	middle := len(list) / 2
+	leftList := copyList(list, 0, middle)
+	rightList := copyList(list, middle, len(list))
+	if len(list) > 1 {
+		MergeSort(leftList)                 //先对左边进行归并排序
+		MergeSort(rightList)                //再对右边进行归并排序
+		mergeAll(list, leftList, rightList) //对左右排序的结果进行组合
+	}
+}
+
+func copyList(list []int, start int, end int) []int {
+	result := make([]int, 0)
+	for i := start; i < end; i++ {
+		result = append(result, list[i])
+	}
+	return result
+}
+
+func mergeAll(array []int, left []int, right []int) {
+	l, r, i := 0, 0, 0 //左数组的下标、右数组的下标、组合数组的下标
+	for l < len(left) && r < len(right) {
+		if left[l] > right[r] {
+			array[i] = right[r]
+			i++
+			r++
+		} else {
+			array[i] = left[l]
+			i++
+			l++
+		}
+	}
+
+	for r < len(right) {
+		array[i] = right[r]
+		r++
+		i++
+	}
+
+	for l < len(left) {
+		array[i] = left[l]
+		l++
+		i++
+	}
+}

util/sort/MergeSort_test.go

@@ -0,0 +1,42 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 11:45
+ *  @Description：
+ */
+
+package sort
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestMergeSort(t *testing.T) {
+	list1 := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	MergeSort(list1)
+	for _, r := range list1 {
+		fmt.Print(r, "  ")
+	}
+	fmt.Println()
+
+	list2 := []int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
+	MergeSort(list2)
+	for _, r := range list2 {
+		fmt.Print(r, "  ")
+	}
+	fmt.Println()
+
+	list3 := []int{100, 5, 222, 312, 552, 354, 8, 21, 90, 2, 0, 12, 345, 67}
+	MergeSort(list3)
+	for _, r := range list3 {
+		fmt.Print(r, "  ")
+	}
+	fmt.Println()
+
+	list4 := []int{1, 19, 42, 7, 3131, 44, 56, 123, 589, 21, 975, 123, 5467, 143, 7, 321, 77, 3}
+	MergeSort(list4)
+	for _, r := range list4 {
+		fmt.Print(r, "  ")
+	}
+	fmt.Println()
+}

util/sort/QuickSort.go

@@ -0,0 +1,46 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 17:06
+ *  @Description：
+ */
+
+package sort
+
+import "Go-Tool/util/search"
+
+//通过hoare划分来实现快速排序
+func QuickSort(list []int, start, end int) {
+	if start < end {
+		position := hoarePartition(list, start, end)
+		QuickSort(list, start, position) //注意这边结束的下表是position，而不是position + 1
+		QuickSort(list, position+1, end)
+	}
+}
+
+//通过lomuto划分来实现快速排序
+func QuickSort1(list []int, start, end int) {
+	if start < end {
+		position := search.LomutoPartition(list, start, end)
+		QuickSort(list, start, position)
+		QuickSort(list, position+1, end)
+	}
+}
+
+func hoarePartition(list []int, start int, end int) int {
+	value := list[start] //比较的元素
+	s := start
+	e := end
+	for s < e {
+		//找到数组终止前，比目标数(value)大的数字
+		for ; s < end && list[s] < value; s++ {
+		}
+		//找到数组结束前，比目标数(value)小的数字
+		for ; e > start && list[e] >= value; e-- {
+		}
+		if s < e {
+			list[s], list[e] = list[e], list[s]
+		}
+	}
+	list[start], list[e] = list[e], list[start]
+	return e
+}

util/sort/QuickSort_test.go

@@ -0,0 +1,80 @@
+/*
+ *  @Author : huangzj
+ *  @Time : 2020/8/19 17:57
+ *  @Description：
+ */
+
+package sort
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestQuickSort(t *testing.T) {
+	list := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	QuickSort(list, 0, len(list)-1)
+
+	for _, r := range list {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list1 := []int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
+	QuickSort(list1, 0, len(list1)-1)
+
+	for _, r := range list1 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list2 := []int{432, 412, 213, 456, 7, 213, 4, 78, 13, 87, 312321, 456, 7, 231, 234, 3}
+	QuickSort(list2, 0, len(list2)-1)
+
+	for _, r := range list2 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list3 := []int{1, 312, 356, 76, 2, 54, 78, 321, 3455, 65732, 123534, 54351, 4213, 123, 56, 6, 732, 123, 44, 51, 5, 61, 543}
+	QuickSort(list3, 0, len(list3)-1)
+
+	for _, r := range list3 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+}
+
+func TestQuickSort1(t *testing.T) {
+	list := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	QuickSort1(list, 0, len(list)-1)
+
+	for _, r := range list {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list1 := []int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
+	QuickSort1(list1, 0, len(list1)-1)
+
+	for _, r := range list1 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list2 := []int{432, 412, 213, 456, 7, 213, 4, 78, 13, 87, 312321, 456, 7, 231, 234, 3}
+	QuickSort1(list2, 0, len(list2)-1)
+
+	for _, r := range list2 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+
+	list3 := []int{1, 312, 356, 76, 2, 54, 78, 321, 3455, 65732, 123534, 54351, 4213, 123, 56, 6, 732, 123, 44, 51, 5, 61, 543}
+	QuickSort1(list3, 0, len(list3)-1)
+
+	for _, r := range list3 {
+		fmt.Print(r, "   ")
+	}
+	fmt.Println()
+}