20240208 Finished

src/problem/mod.rs

@@ -41,3 +41,4 @@ mod p292_nim_game;
 mod p1696_jump_game_vi;
 mod lcp30_magic_tower;
 mod p2641_cousins_in_binary_tree_ii;
+mod p993_cousins_in_binary_tree;

src/problem/p993_cousins_in_binary_tree.rs

@@ -0,0 +1,112 @@
+/**
+ * [993] Cousins in Binary Tree
+ */
+pub struct Solution {}
+
+use crate::util::tree::{TreeNode, to_tree};
+
+// submission codes start here
+
+// 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
+//     }
+//   }
+// }
+use std::rc::Rc;
+use std::cell::RefCell;
+
+struct Tree {
+    root: Rc<RefCell<TreeNode>>,
+    x: i32,
+    x_height: usize,
+    x_parent: i32,
+    y: i32,
+    y_height: usize,
+    y_parent: i32
+}
+
+impl Tree {
+    fn new(root: Rc<RefCell<TreeNode>>, x: i32, y: i32) -> Tree {
+        return Tree {
+            root,
+            x,
+            x_height: 0,
+            x_parent: 0,
+            y,
+            y_height: 0,
+            y_parent: 0
+        }
+    }
+
+    fn dfs(&mut self, node: &Rc<RefCell<TreeNode>>, height: usize, parent: i32) {
+        let (mut x_find, mut y_find) = (false, false);
+
+        if node.borrow().val == self.x {
+            self.x_height = height;
+            self.x_parent = parent;
+
+            x_find = true;
+        }
+
+        if node.borrow().val == self.y {
+            self.y_height = height;
+            self.y_parent = parent;
+
+            y_find = true;
+        }
+
+        if x_find && y_find {
+            return;
+        }
+
+        if let Some(left) = &node.borrow().left {
+            self.dfs(left, height + 1, node.borrow().val);
+        }
+
+        if let Some(right) = &node.borrow().right {
+            self.dfs(right, height + 1, node.borrow().val);
+        }
+    }
+}
+
+impl Solution {
+    pub fn is_cousins(root: Option<Rc<RefCell<TreeNode>>>, x: i32, y: i32) -> bool {
+        let root = if let Some(r) = root {
+            r
+        } else {
+            return false;
+        };
+
+        let mut tree = Tree::new(Rc::clone(&root), x, y);
+        tree.dfs(&root, 0, -1);
+
+
+        tree.x_height == tree.y_height && tree.x_parent != tree.y_parent
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_993() {
+        assert!(!Solution::is_cousins(to_tree(vec![Some(1),Some(2),Some(3),Some(4)]),
+                                      4, 3));
+    }
+}