70 lines
1.5 KiB
Rust
70 lines
1.5 KiB
Rust
/**
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* [112] Path Sum
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*/
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pub struct Solution {}
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use crate::util::tree::{to_tree, TreeNode};
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// submission codes start here
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// Definition for a binary tree node.
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// #[derive(Debug, PartialEq, Eq)]
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// pub struct TreeNode {
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// pub val: i32,
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// pub left: Option<Rc<RefCell<TreeNode>>>,
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// pub right: Option<Rc<RefCell<TreeNode>>>,
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// }
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//
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// impl TreeNode {
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// #[inline]
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// pub fn new(val: i32) -> Self {
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// TreeNode {
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// val,
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// left: None,
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// right: None
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// }
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// }
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// }
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use std::cell::RefCell;
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use std::rc::Rc;
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impl Solution {
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fn dfs(node: &Rc<RefCell<TreeNode>>, current_sum: i32, target_sum: i32) -> bool {
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// 到达叶子节点
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if node.borrow().left.is_none() && node.borrow().right.is_none() {
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return current_sum + node.borrow().val == target_sum;
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}
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if let Some(left) = &node.borrow().left {
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if Self::dfs(left, current_sum + node.borrow().val, target_sum) {
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return true;
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}
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}
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if let Some(right) = &node.borrow().right {
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if Self::dfs(right, current_sum + node.borrow().val, target_sum) {
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return true;
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}
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}
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false
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}
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pub fn has_path_sum(root: Option<Rc<RefCell<TreeNode>>>, target_sum: i32) -> bool {
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if let Some(root) = root {
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return Self::dfs(&root, 0, target_sum);
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}
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false
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}
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}
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// submission codes end
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_112() {}
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}
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