Leetcode

path-sum-112/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "path-sum-112"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

path-sum-112/src/main.rs

@@ -0,0 +1,50 @@
+// Definition for a binary tree node.
+#[derive(Debug, PartialEq, Eq)]
+pub struct TreeNode {
+    pub val: i32,
+    pub left: Option<Rc<RefCell<TreeNode>>>,
+    pub right: Option<Rc<RefCell<TreeNode>>>,
+}
+
+impl TreeNode {
+    #[inline]
+    pub fn new(val: i32) -> Self {
+        TreeNode {
+            val,
+            left: None,
+            right: None,
+        }
+    }
+}
+
+struct Solution;
+
+use std::cell::RefCell;
+use std::rc::Rc;
+impl Solution {
+    pub fn has_path_sum(root: Option<Rc<RefCell<TreeNode>>>, target_sum: i32) -> bool {
+        // Base case: If the tree is empty, there's no path
+        if root.is_none() {
+            return false;
+        }
+
+        let node = root.unwrap();
+        let node_ref = node.borrow();
+        let current_val = node_ref.val;
+
+        // If this is a leaf node, check if the value equals the remaining target sum
+        if node_ref.left.is_none() && node_ref.right.is_none() {
+            return current_val == target_sum;
+        }
+
+        // Otherwise, check if either subtree has a path with the remaining sum
+        let remaining_sum = target_sum - current_val;
+
+        Solution::has_path_sum(node_ref.left.clone(), remaining_sum)
+            || Solution::has_path_sum(node_ref.right.clone(), remaining_sum)
+    }
+}
+
+fn main() {
+    println!("Hello, world!");
+}