199. 二叉树的右视图

src/main.rs

@@ -3,28 +3,29 @@ mod tree;
 
 use crate::tree::{TreeNode, build_tree_from_str};
 struct Solution {}
-use std::cell::RefCell;
 use std::rc::Rc;
+use std::cell::RefCell;
 impl Solution {
-    pub fn max_path_sum(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
-        let (_,ans) = Self::dfs(&root);
-        ans
+    pub fn right_side_view(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
+        let mut result = vec![];
+        Self::dfs(root, &mut result,0);
+        result
     }
-    fn dfs(root: &Option<Rc<RefCell<TreeNode>>>) -> (i32, i32) {
+    fn dfs(root: Option<Rc<RefCell<TreeNode>>>, mut arr: &mut Vec<i32>,depth: usize) {
         if root.is_none() {
-            return (-100000000, -100000000);
+            return;
         }
-        let (la, ln) = Self::dfs(&root.as_ref().unwrap().borrow().left);
-        let (ra, rn) = Self::dfs(&root.as_ref().unwrap().borrow().right);
-        let val = root.as_ref().unwrap().borrow().val;
-        let a = val.max(val + la).max(val + ra);
-        let n = a.max(ln).max(rn).max(val + la + ra);
-        (a, n)
+        while arr.len() <= depth {
+            arr.push(0);
+        }
+        (*arr)[depth] = root.as_ref().unwrap().borrow().val;
+        Self::dfs(root.as_ref().unwrap().borrow().left.clone(), &mut arr,depth + 1);
+        Self::dfs(root.as_ref().unwrap().borrow().right.clone(), &mut arr,depth + 1);
     }
 }
 fn main() {
     println!(
         "{:?}",
-        Solution::max_path_sum(build_tree_from_str("[5,4,8,11,null,13,4,7,2,null,null,null,1]"))
+        Solution::right_side_view(build_tree_from_str("[1,2,3,4,null,null,null,5]"))
     );
 }