Add solution and test-cases for problem 897

Author: 0xff-dev

leetcode/801-900/0897.Increasing-Order-Search-Tree/README.md

@@ -1,28 +1,24 @@
 # [897.Increasing Order Search Tree][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+Given the `root` of a binary search tree, rearrange the tree in **in-order** so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only one right child.
 
-**Example 1:**
+**Example 1:**  
+![example1](./ex1.jpg)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: root = [5,3,6,2,4,null,8,1,null,null,null,7,9]
+Output: [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9]
 ```
 
-## 题意
-> ...
+**Example 2:**  
+![example2](./ex2.jpg)
 
-## 题解
 
-### 思路1
-> ...
-Increasing Order Search Tree
-```go
 ```
-
+Input: root = [5,1,7]
+Output: [1,null,5,null,7]
+```
 
 ## 结语
 

leetcode/801-900/0897.Increasing-Order-Search-Tree/Solution.go

@@ -1,5 +1,37 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+type TreeNode struct {
+	Val         int
+	Left, Right *TreeNode
+}
+
+func Solution(root *TreeNode) *TreeNode {
+	if root == nil {
+		return nil
+	}
+
+	var tree, walker *TreeNode
+	var inOrder func(*TreeNode)
+	inOrder = func(root *TreeNode) {
+		if root == nil {
+			return
+		}
+		if root.Left != nil {
+			inOrder(root.Left)
+		}
+
+		n := &TreeNode{Val: root.Val}
+		if tree == nil {
+			tree = n
+			walker = n
+		} else {
+			walker.Right = n
+			walker = walker.Right
+		}
+		if root.Right != nil {
+			inOrder(root.Right)
+		}
+	}
+	inOrder(root)
+	return tree
 }

leetcode/801-900/0897.Increasing-Order-Search-Tree/Solution_test.go

@@ -10,12 +10,67 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs *TreeNode
+		expect *TreeNode
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", &TreeNode{
+			Val: 5,
+			Left: &TreeNode{
+				Val:   3,
+				Right: &TreeNode{Val: 4},
+				Left: &TreeNode{
+					Val:  2,
+					Left: &TreeNode{Val: 1},
+				},
+			},
+			Right: &TreeNode{
+				Val: 6,
+				Right: &TreeNode{
+					Val:   8,
+					Left:  &TreeNode{Val: 7},
+					Right: &TreeNode{Val: 9},
+				},
+			},
+		}, &TreeNode{
+			Val: 1,
+			Right: &TreeNode{
+				Val: 2,
+				Right: &TreeNode{
+					Val: 3,
+					Right: &TreeNode{
+						Val: 4,
+						Right: &TreeNode{
+							Val: 5,
+							Right: &TreeNode{
+								Val: 6,
+								Right: &TreeNode{
+									Val: 7,
+									Right: &TreeNode{
+										Val: 8,
+										Right: &TreeNode{
+											Val: 9,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		}},
+		{"TestCase2", &TreeNode{
+			Val:   5,
+			Left:  &TreeNode{Val: 1},
+			Right: &TreeNode{Val: 7},
+		}, &TreeNode{
+			Val: 1,
+			Right: &TreeNode{
+				Val: 5,
+				Right: &TreeNode{
+					Val: 7,
+				},
+			},
+		}},
 	}
 
 	//	开始测试
@@ -30,10 +85,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }