Add: Invert Binary Tree

internal/leetcode/problems_status.go

@@ -78,6 +78,7 @@ var problemStatus = map[int]bool{
 	215:  true,
 	217:  true,
 	219:  true,
+	226:  true,
 	231:  true,
 	233:  true,
 	234:  true,

problems/invert-binary-tree/invert_binary_tree.go

@@ -1 +1,23 @@
 package problem226
+
+import "github.com/openset/leetcode/internal/kit"
+
+// TreeNode - Definition for a binary tree node.
+type TreeNode = kit.TreeNode
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func invertTree(root *TreeNode) *TreeNode {
+	if root != nil {
+		root.Left, root.Right = root.Right, root.Left
+		invertTree(root.Left)
+		invertTree(root.Right)
+	}
+	return root
+}

problems/invert-binary-tree/invert_binary_tree_test.go

@@ -1 +1,29 @@
 package problem226
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/openset/leetcode/internal/kit"
+)
+
+type testType struct {
+	in   []int
+	want []int
+}
+
+func TestInvertTree(t *testing.T) {
+	tests := [...]testType{
+		{
+			in:   []int{4, 2, 7, 1, 3, 6, 9},
+			want: []int{4, 7, 2, 9, 6, 3, 1},
+		},
+	}
+	for _, tt := range tests {
+		out := invertTree(kit.SliceInt2TreeNode(tt.in))
+		got := kit.TreeNode2SliceInt(out)
+		if !reflect.DeepEqual(got, tt.want) {
+			t.Fatalf("in: %v, got: %v, want: %v", tt.in, got, tt.want)
+		}
+	}
+}