添加新题目

二叉树/二叉树展开为链表/main.go

@@ -0,0 +1,41 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func main() {
+
+}
+func flatten(root *TreeNode) {
+	var helper func(root *TreeNode) []int
+	helper = func(root *TreeNode) []int {
+		if root == nil {
+			return []int{}
+		}
+		tmp := make([]int, 0)
+		tmp = append(tmp, root.Val)
+		tmp = append(tmp, helper(root.Left)...)
+		tmp = append(tmp, helper(root.Right)...)
+
+		return tmp
+	}
+	res := helper(root)
+	cur := root
+	for i := 0; i < len(res); i++ {
+		if i == 0 {
+			cur.Left = nil
+			continue
+		}
+		cur.Left = nil
+		tmpNode := &TreeNode{
+			Val:   res[i],
+			Left:  nil,
+			Right: nil,
+		}
+		cur.Right = tmpNode
+		cur = tmpNode
+	}
+}