Latest May problem

problems/993/main.py

@@ -0,0 +1,52 @@
+# Definition for a binary tree node.
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+    
+    def __init__(self):
+        self.xPar = None
+        self.xDepth = None
+        self.yPar = None
+        self.yDepth = None
+        
+    def isCousins(self, root: TreeNode, x: int, y: int) -> bool:
+        # descend the binary tree and find the two values, set their parents
+        # exit and then compare
+        # because ints are unique and the nodes do exist there
+        # shouldn't be too many edge cases I don't think
+        self.descendTreeFinding(root, x, y, None, 0)
+        return self.xDepth == self.yDepth and self.xPar != self.yPar
+    
+    def descendTreeFinding(self, tree, x, y, parent, depth):
+        if tree is None:
+            return
+        
+        if tree.val == x:
+            self.xPar = parent
+            self.xDepth = depth
+            
+        if tree.val == y:
+            self.yPar = parent
+            self.yDepth = depth
+            
+        if self.yPar is not None and self.xPar is not None:
+            return
+        else:
+            self.descendTreeFinding(tree.left, x, y, tree.val, depth + 1)
+            self.descendTreeFinding(tree.right, x, y, tree.val, depth + 1)
+
+s = Solution()
+print("Expected: true")
+tree = TreeNode(1)
+left = TreeNode(2)
+left.right = TreeNode(4)
+tree.left = left
+right = TreeNode(3)
+right.right = TreeNode(5)
+tree.right = right
+
+print("Got:", s.isCousins(tree, 4, 5))

problems/993/problem.txt

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+In a binary tree, the root node is at depth 0, and children of each depth k node are at depth k+1.
+
+Two nodes of a binary tree are cousins if they have the same depth, but have different parents.
+
+We are given the root of a binary tree with unique values, and the values x and y of two different nodes in the tree.
+
+Return true if and only if the nodes corresponding to the values x and y are cousins.
+
+ 
+
+Example 1:
+
+Input: root = [1,2,3,4], x = 4, y = 3
+Output: false
+
+Example 2:
+
+Input: root = [1,2,3,null,4,null,5], x = 5, y = 4
+Output: true
+
+Example 3:
+
+Input: root = [1,2,3,null,4], x = 2, y = 3
+Output: false
+
+ 
+
+Note:
+
+    The number of nodes in the tree will be between 2 and 100.
+    Each node has a unique integer value from 1 to 100.

problems/993/run.sh

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+#!/bin/bash
+
+python3 main.py