finish minimum absolute difference in bst

11-50/minimum-absolute-difference-in-bst/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "minimum-absolute-difference-in-bst"
+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]

11-50/minimum-absolute-difference-in-bst/src/main.rs

@@ -0,0 +1,58 @@
+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 get_minimum_difference_loop(node: Option<&Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
+        if let Some(x) = node {
+            let val = x.borrow();
+            Solution::get_minimum_difference_loop(val.left.as_ref(), result);
+            result.push(val.val);
+            Solution::get_minimum_difference_loop(val.right.as_ref(), result);
+        }
+    }
+
+    pub fn get_minimum_difference(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        let mut vec: Vec<i32> = Vec::new();
+        Solution::get_minimum_difference_loop(root.as_ref(), &mut vec);
+        let mut result: i32 = i32::MAX;
+        let mut prefix: i32 = vec[0];
+        for v in vec.iter().skip(1) {
+            let t: i32 = *v - prefix;
+            if t < result {
+                result = t;
+            }
+            prefix = *v;
+        }
+        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))));
+    println!(
+        "Minimum absolute difference: {}",
+        Solution::get_minimum_difference(Some(Rc::new(RefCell::new(node))))
+    );
+}