Created
March 15, 2020 13:41
-
-
Save qianyan/d351a385dd50e90ca26bbfe13665aa2d to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
pub mod two_sum_bst { | |
use std::rc::Rc; | |
use std::cell::RefCell; | |
#[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 | |
} | |
} | |
} | |
pub fn find_target(root: Option<Rc<RefCell<TreeNode>>>, k: i32) -> bool { | |
// transform TreeNode to sorted seq. | |
let v = to_vec(&root); | |
println!("the vec is {:?}", v); | |
two_sum2(v, k) | |
} | |
fn two_sum2(numbers: Vec<i32>, target: i32) -> bool { | |
for i in 0..numbers.len() { | |
if let Some(j) = &numbers[(i+1)..].binary_search(&(target - numbers[i])).ok() { | |
return true; | |
} | |
} | |
false | |
} | |
fn to_vec(root: &Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> { | |
match root { | |
Some(r) => { | |
let mut v = to_vec(&r.borrow_mut().left); | |
v.extend(vec![r.borrow_mut().val]); | |
v.extend(to_vec(&r.borrow_mut().right)); | |
v | |
} | |
None => vec![] | |
} | |
} | |
#[test] | |
fn test_two_sum_bst() { | |
let root = Some(Rc::new( | |
RefCell::new( | |
TreeNode{val: 7, | |
left: Some(Rc::new( | |
RefCell::new( | |
TreeNode::new(2)))), | |
right: Some(Rc::new( | |
RefCell::new( | |
TreeNode{ val: 11, | |
left: None, | |
right: Some(Rc::new( | |
RefCell::new( | |
TreeNode::new(15))))} | |
))) | |
}))); | |
let found = find_target(root, 26); | |
assert_eq!(found, true); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment