From c140cc8ca29b2e099c4aa07d4e3901d6f7b581a7 Mon Sep 17 00:00:00 2001
From: chayan das <110921638+Chayandas07@users.noreply.github.com>
Date: Thu, 24 Oct 2024 00:03:25 +0530
Subject: [PATCH] Create 2641. Cousins in Binary Tree II

---
 2641. Cousins in Binary Tree II | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 2641. Cousins in Binary Tree II

diff --git a/2641. Cousins in Binary Tree II b/2641. Cousins in Binary Tree II
new file mode 100644
index 0000000..55bf651
--- /dev/null
+++ b/2641. Cousins in Binary Tree II	
@@ -0,0 +1,30 @@
+class Solution {
+public:
+    TreeNode* replaceValueInTree(TreeNode* root) {
+        queue<pair<TreeNode*, int>> qu;
+        qu.push({root, 0});
+        int prev = 0;
+
+        while(!qu.empty()) {
+            int n = qu.size();
+            int temp = 0;
+            for(int i = 0; i < n; i++) {
+                auto [curr, value] = qu.front(); qu.pop();
+
+                curr -> val = (prev - value);
+                int siblings = 0;
+                
+                if(curr -> right) siblings += curr -> right -> val;
+                if(curr -> left) {
+                    siblings += curr -> left -> val;
+                    qu.push({curr -> left, siblings});
+                }
+                if(curr -> right) qu.push({curr -> right, siblings});
+                
+                temp += siblings;
+            }
+            prev = temp;
+        }
+        return root;
+    }
+};