add sol

leetcode/590.N-aryTreePostorderTraversal/sol.go

@@ -0,0 +1,41 @@
+package main
+
+import "fmt"
+
+/**
+ * Definition for a Node.
+ * type Node struct {
+ *     Val int
+ *     Children []*Node
+ * }
+ */
+
+type Node struct {
+	Val      int
+	Children []*Node
+}
+
+func postorder(root *Node) []int {
+	if root == nil {
+		return []int{}
+	}
+
+	res := []int{}
+	for _, child := range root.Children {
+		res = append(res, postorder(child)...)
+	}
+	res = append(res, root.Val)
+
+	return res
+}
+
+func main() {
+	root := &Node{Val: 1}
+	child1 := &Node{Val: 3, Children: []*Node{{Val: 5}, {Val: 6}}}
+	child2 := &Node{Val: 2}
+	child3 := &Node{Val: 4}
+	root.Children = []*Node{child1, child2, child3}
+
+	result := postorder(root)
+	fmt.Println(result)
+}