finish increasing order search tree

18-50/increasing-order-search-tree/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "increasing-order-search-tree"
+version = "0.1.0"
+authors = ["Checky-Hu <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

18-50/increasing-order-search-tree/src/main.rs

@@ -0,0 +1,52 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+#[derive(Debug, PartialEq, Eq)]
+struct TreeNode {
+    val: i32,
+    left: Option<Rc<RefCell<TreeNode>>>,
+    right: Option<Rc<RefCell<TreeNode>>>,
+}
+
+impl TreeNode {
+    #[inline]
+    fn new(val: i32) -> Self {
+        TreeNode {
+            val,
+            left: None,
+            right: None,
+        }
+    }
+}
+
+struct Solution {}
+
+impl Solution {
+    fn post_order_loop(node: Option<&Rc<RefCell<TreeNode>>>, vec: &mut Vec<i32>) {
+        if let Some(x) = node {
+            let v = x.borrow();
+            Solution::post_order_loop(v.right.as_ref(), vec);
+            vec.push(v.val);
+            Solution::post_order_loop(v.left.as_ref(), vec);
+        }
+    }
+
+    pub fn increasing_bst(root: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
+        let mut vec: Vec<i32> = Vec::new();
+        Solution::post_order_loop(root.as_ref(), &mut vec);
+        let mut result: Option<Rc<RefCell<TreeNode>>> = None;
+        for v in vec.iter() {
+            let mut node: TreeNode = TreeNode::new(*v);
+            node.right = result;
+            result = Some(Rc::new(RefCell::new(node)));
+        }
+        result
+    }
+}
+
+fn main() {
+    let mut node = TreeNode::new(2);
+    node.left = Some(Rc::new(RefCell::new(TreeNode::new(1))));
+    node.right = Some(Rc::new(RefCell::new(TreeNode::new(3))));
+    Solution::increasing_bst(Some(Rc::new(RefCell::new(node))));
+}