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.go

@@ -0,0 +1,37 @@
+// File: build_tree.go
+// Created Time: 2023-07-20
+// Author: hongyun-robot (1836017030@qq.com)
+
+package chapter_divide_and_conquer
+
+import . "github.com/krahets/hello-algo/pkg"
+
+/* 构建二叉树：分治 */
+func dfsBuildTree(preorder, inorder []int, hmap map[int]int, i, l, r int) *TreeNode {
+	// 子树区间为空时终止
+	if r-l < 0 {
+		return nil
+	}
+	// 初始化根节点
+	root := NewTreeNode(preorder[i])
+	// 查询 m ，从而划分左右子树
+	m := hmap[preorder[i]]
+	// 子问题：构建左子树
+	root.Left = dfsBuildTree(preorder, inorder, hmap, i+1, l, m-1)
+	// 子问题：构建右子树
+	root.Right = dfsBuildTree(preorder, inorder, hmap, i+1+m-l, m+1, r)
+	// 返回根节点
+	return root
+}
+
+/* 构建二叉树 */
+func buildTree(preorder, inorder []int) *TreeNode {
+	// 初始化哈希表，存储 inorder 元素到索引的映射
+	hmap := make(map[int]int, len(inorder))
+	for i := 0; i < len(inorder); i++ {
+		hmap[inorder[i]] = i
+	}
+
+	root := dfsBuildTree(preorder, inorder, hmap, 0, 0, len(inorder)-1)
+	return root
+}