108 accepted. 259ms > 248ms.

Author: aQua

Algorithms/0108.convert-sorted-array-to-binary-search-tree/README.md

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+# [108. Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/)
+
+## 题目
+Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
+
+## 解题思路
+> 高度平衡二叉树是每一个节点的两个子树的深度差不能超过1。
+见程序注释

Algorithms/0108.convert-sorted-array-to-binary-search-tree/convert-sorted-array-to-binary-search-tree.go

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+package Problem0108
+
+import (
+	"github.com/aQuaYi/LeetCode-in-Golang/kit"
+)
+
+type TreeNode = kit.TreeNode
+
+func sortedArrayToBST(nums []int) *TreeNode {
+	n := len(nums)
+	if n == 0 {
+		return nil
+	}
+
+	if n == 1 {
+		return &TreeNode{
+			Val: nums[0],
+		}
+	}
+
+	return &TreeNode{
+		Val:   nums[n/2],
+		Left:  sortedArrayToBST(nums[:n/2]),
+		Right: sortedArrayToBST(nums[n/2+1:]),
+	}
+}

Algorithms/0108.convert-sorted-array-to-binary-search-tree/convert-sorted-array-to-binary-search-tree_test.go

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+package Problem0108
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/aQuaYi/LeetCode-in-Golang/kit"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Problem0108(t *testing.T) {
+	ast := assert.New(t)
+
+	// tcs is testcase slice
+	tcs := []struct {
+		nums []int
+		pre  []int
+	}{
+
+		{
+			[]int{},
+			nil,
+		},
+
+		{
+			[]int{1, 2, 3, 4, 5, 6, 7},
+			[]int{4, 2, 1, 3, 6, 5, 7},
+		},
+
+		// 可以多个 testcase
+	}
+
+	for _, tc := range tcs {
+		fmt.Printf("~~%v~~\n", tc)
+
+		ast.Equal(tc.pre, kit.Tree2Preorder(sortedArrayToBST(tc.nums)), "输入:%v", tc)
+	}
+}