feat(sort/search): support heap/selection_sort/binary_search_edge in go code (#521)

* feat(go): support binary search edge and testcase

* feat(go): support selection sort and testcase

* feat(go): support heap sort and testcase

* Update selection_sort_test.go

* Update selection_sort.go

* Update heap_sort.go

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/go/chapter_sorting/heap_sort.go

@@ -0,0 +1,44 @@
+// File: heap_sort.go
+// Created Time: 2023-05-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_sorting
+
+/* 堆的长度为 n ，从节点 i 开始，从顶至底堆化 */
+func siftDown(nums *[]int, n, i int) {
+	for true {
+		// 判断节点 i, l, r 中值最大的节点，记为 ma
+		l := 2*i + 1
+		r := 2*i + 2
+		ma := i
+		if l < n && (*nums)[l] > (*nums)[ma] {
+			ma = l
+		}
+		if r < n && (*nums)[r] > (*nums)[ma] {
+			ma = r
+		}
+		// 若节点 i 最大或索引 l, r 越界，则无需继续堆化，跳出
+		if ma == i {
+			break
+		}
+		// 交换两节点
+		(*nums)[i], (*nums)[ma] = (*nums)[ma], (*nums)[i]
+		// 循环向下堆化
+		i = ma
+	}
+}
+
+/* 堆排序 */
+func heapSort(nums *[]int) {
+	// 建堆操作：堆化除叶节点以外的其他所有节点
+	for i := len(*nums)/2 - 1; i >= 0; i-- {
+		siftDown(nums, len(*nums), i)
+	}
+	// 从堆中提取最大元素，循环 n-1 轮
+	for i := len(*nums) - 1; i > 0; i-- {
+		// 交换根节点与最右叶节点（即交换首元素与尾元素）
+		(*nums)[0], (*nums)[i] = (*nums)[i], (*nums)[0]
+		// 以根节点为起点，从顶至底进行堆化
+		siftDown(nums, i, 0)
+	}
+}

codes/go/chapter_sorting/heap_sort_test.go

@@ -0,0 +1,16 @@
+// File: heap_sort_test.go
+// Created Time: 2023-05-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_sorting
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestHeapSort(t *testing.T) {
+	nums := []int{4, 1, 3, 1, 5, 2}
+	heapSort(&nums)
+	fmt.Println("堆排序完成后 nums = ", nums)
+}

codes/go/chapter_sorting/selection_sort.go

@@ -0,0 +1,24 @@
+// File: selection_sort.go
+// Created Time: 2023-05-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_sorting
+
+/* 选择排序 */
+func selectionSort(nums []int) {
+	n := len(nums)
+	// 外循环：未排序区间为 [i, n-1]
+	for i := 0; i < n-1; i++ {
+		// 内循环：找到未排序区间内的最小元素
+		k := i
+		for j := i + 1; j < n; j++ {
+			if nums[j] < nums[k] {
+				// 记录最小元素的索引
+				k = j
+			}
+		}
+		// 将该最小元素与未排序区间的首个元素交换
+		nums[i], nums[k] = nums[k], nums[i]
+
+	}
+}

codes/go/chapter_sorting/selection_sort_test.go

@@ -0,0 +1,16 @@
+// File: selection_sort_test.go
+// Created Time: 2023-05-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_sorting
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestSelectionSort(t *testing.T) {
+	nums := []int{4, 1, 3, 1, 5, 2}
+	selectionSort(nums)
+	fmt.Println("选择排序完成后 nums = ", nums)
+}