Merge pull request #588 from 0xff-dev/951

Add solution and test-cases for problem 951

leetcode/901-1000/0951.Flip-Equivalent-Binary-Trees/README.md

@@ -1,28 +1,35 @@
 # [951.Flip Equivalent Binary Trees][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
+For a binary tree **T**, we can define a **flip operation** as follows: choose any node, and swap the left and right child subtrees.
+
+A binary tree **X** is flip equivalent to a binary tree **Y** if and only if we can make **X** equal to **Y** after some number of flip operations.
+
+Given the roots of two binary trees `root1` and `root2`, return `true` if the two trees are flip equivalent or `false` otherwise.
 
-**Example 1:**
+**Example 1:**  
+
+![example1](./tree_ex.png)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: root1 = [1,2,3,4,5,6,null,null,null,7,8], root2 = [1,3,2,null,6,4,5,null,null,null,null,8,7]
+Output: true
+Explanation: We flipped at nodes with values 1, 3, and 5.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Flip Equivalent Binary Trees
-```go
 ```
+Input: root1 = [], root2 = []
+Output: true
+```
+
+**Example 3:**
 
+```
+Input: root1 = [], root2 = [1]
+Output: false
+```
 
 ## 结语
 

leetcode/901-1000/0951.Flip-Equivalent-Binary-Trees/Solution.go

@@ -1,5 +1,31 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+type TreeNode struct {
+	Val         int
+	Left, Right *TreeNode
+}
+
+func Solution(root1 *TreeNode, root2 *TreeNode) bool {
+	if root1 == nil && root2 == nil {
+		return true
+	}
+	if root1 == nil || root2 == nil {
+		return false
+	}
+
+	if root1.Val != root2.Val {
+		return false
+	}
+	a := Solution(root1.Left, root2.Left)
+	b := Solution(root1.Right, root2.Right)
+
+	if a && b {
+		return true
+	}
+	a = Solution(root1.Left, root2.Right)
+	b = Solution(root1.Right, root2.Left)
+	if a && b {
+		return true
+	}
+	return false
 }

leetcode/901-1000/0951.Flip-Equivalent-Binary-Trees/Solution_test.go

@@ -10,30 +10,62 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		t1, t2 *TreeNode
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", &TreeNode{
+			Val: 1,
+			Left: &TreeNode{
+				Val:  2,
+				Left: &TreeNode{Val: 4},
+				Right: &TreeNode{
+					Val:   5,
+					Left:  &TreeNode{Val: 7},
+					Right: &TreeNode{Val: 8},
+				},
+			},
+			Right: &TreeNode{
+				Val:  3,
+				Left: &TreeNode{Val: 6},
+			},
+		}, &TreeNode{
+			Val: 1,
+			Left: &TreeNode{
+				Val:   3,
+				Right: &TreeNode{Val: 6},
+			},
+			Right: &TreeNode{
+				Val: 2,
+				Left: &TreeNode{
+					Val: 4,
+				},
+				Right: &TreeNode{
+					Val:   5,
+					Left:  &TreeNode{Val: 8},
+					Right: &TreeNode{Val: 7},
+				},
+			},
+		}, true},
+		{"TestCase1", nil, nil, true},
+		{"TestCase2", nil, &TreeNode{Val: 1}, false},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.t1, c.t2)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.t1, c.t2)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }