129. 求根节点到叶节点数字之和

src/main.rs

@@ -5,26 +5,31 @@ mod list;
 mod tree;
 
 struct Solution {}
+
+use crate::tree::{TreeNode, build_tree_from_str};
+use std::cell::RefCell;
+use std::rc::Rc;
+
 impl Solution {
-    pub fn maximum_length_substring(s: String) -> i32 {
+    pub fn sum_numbers(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
-        let s = s.bytes().map(|x| x as usize).collect::<Vec<_>>();
+        Self::dfs(root).iter().map(|x| x.parse::<i32>().unwrap()).sum()
-        let mut arr = vec![0; 'z' as usize + 1];
-        let mut l = 0;
-        let mut ans = 0;
-        for r in 0..s.len() {
-            arr[s[r]] += 1;
-            while arr[s[r]] > 2 {
-                arr[s[l]] -= 1;
-                l += 1;
     }
-            ans = ans.max(r - l + 1);
+    pub fn dfs(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<String> {
+        if root.is_none() {
+            return vec![];
         }
-        ans as i32
+        let x = root.as_ref().unwrap();
+        let mut arr = Self::dfs(Rc::clone(x).borrow().left.clone());
+        arr.append(&mut Self::dfs(Rc::clone(x).borrow().right.clone()));
+        if arr.is_empty() {
+            return vec![x.borrow().val.to_string()];
+        }
+        arr.iter().map(|y| x.borrow().val.to_string() + y).collect()
     }
 }
 fn main() {
     println!(
         "{:?}",
-        Solution::maximum_length_substring("bcbbbcba".to_string())
+        Solution::sum_numbers(build_tree_from_str("[4,9,0,5,1]"))
     );
 }