From 29f2194d56a7c531f808f390c8d025cf8921da15 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Wed, 23 Oct 2024 23:39:09 +0200
Subject: [PATCH] =?UTF-8?q?java:=20add=20=C2=AB2641.=20Cousins=20in=20Bina?=
 =?UTF-8?q?ry=20Tree=20II=C2=BB?=
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URL:	https://leetcode.com/problems/cousins-in-binary-tree-ii/
Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 java/cousins-in-binary-tree-ii.java | 51 +++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 java/cousins-in-binary-tree-ii.java

diff --git a/java/cousins-in-binary-tree-ii.java b/java/cousins-in-binary-tree-ii.java
new file mode 100644
index 0000000..706e47c
--- /dev/null
+++ b/java/cousins-in-binary-tree-ii.java
@@ -0,0 +1,51 @@
+class Solution {
+  private int get(TreeNode node) {
+    if (node == null) {
+      return 0;
+    }
+    return node.val;
+  }
+
+  private void handleNode(Queue<TreeNode> q, int siblings, TreeNode node) {
+    if (node == null) {
+      return;
+    }
+
+    node.val = siblings;
+    q.offer(node);
+  }
+
+  private int handleLevel(Queue<TreeNode> q, int previous) {
+    int sum = 0;
+
+    for (int i = q.size(); i > 0; --i) {
+      var node = q.poll();
+      node.val = previous - node.val;
+
+      var siblings = get(node.left) + get(node.right);
+      handleNode(q, siblings, node.left);
+      handleNode(q, siblings, node.right);
+
+      sum += siblings;
+    }
+
+    return sum;
+  }
+
+  public TreeNode replaceValueInTree(TreeNode root) {
+    if (root == null) {
+      return root;
+    }
+
+    Queue<TreeNode> q = new ArrayDeque<>();
+
+    int sumAbove = root.val;
+    q.offer(root);
+
+    while (!q.isEmpty()) {
+      sumAbove = handleLevel(q, sumAbove);
+    }
+
+    return root;
+  }
+}