Add divide and conquer go code (#638)

* feat: Add Go code to binary search recursion under divide and conquer

* style: Code comment standardization

* style: modify function comment

* fix: fixed error when the list is empty

* Update print_utils.go

* Delete print_utils_test.go

* feat: add Go code to divide and conquer

* Update build_tree.go

* style: modify function name

---------

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

codes/go/chapter_divide_and_conquer/build_tree_test.go

@@ -0,0 +1,24 @@
+// File: build_tree_test.go
+// Created Time: 2023-07-20
+// Author: hongyun-robot (1836017030@qq.com)
+
+package chapter_divide_and_conquer
+
+import (
+	"fmt"
+	. "github.com/krahets/hello-algo/pkg"
+	"testing"
+)
+
+func TestBuildTree(t *testing.T) {
+	preorder := []int{3, 9, 2, 1, 7}
+	inorder := []int{9, 3, 1, 2, 7}
+	fmt.Print("前序遍历 = ")
+	PrintSlice(preorder)
+	fmt.Print("中序遍历 = ")
+	PrintSlice(inorder)
+
+	root := buildTree(preorder, inorder)
+	fmt.Println("构建的二叉树为：")
+	PrintTree(root)
+}