Add solution #1315

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,227 LeetCode solutions in JavaScript
+# 1,228 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -996,6 +996,7 @@
 1312|[Minimum Insertion Steps to Make a String Palindrome](./solutions/1312-minimum-insertion-steps-to-make-a-string-palindrome.js)|Hard|
 1313|[Decompress Run-Length Encoded List](./solutions/1313-decompress-run-length-encoded-list.js)|Easy|
 1314|[Matrix Block Sum](./solutions/1314-matrix-block-sum.js)|Medium|
+1315|[Sum of Nodes with Even-Valued Grandparent](./solutions/1315-sum-of-nodes-with-even-valued-grandparent.js)|Medium|
 1317|[Convert Integer to the Sum of Two No-Zero Integers](./solutions/1317-convert-integer-to-the-sum-of-two-no-zero-integers.js)|Easy|
 1318|[Minimum Flips to Make a OR b Equal to c](./solutions/1318-minimum-flips-to-make-a-or-b-equal-to-c.js)|Medium|
 1319|[Number of Operations to Make Network Connected](./solutions/1319-number-of-operations-to-make-network-connected.js)|Medium|

solutions/1315-sum-of-nodes-with-even-valued-grandparent.js

@@ -0,0 +1,39 @@
+/**
+ * 1315. Sum of Nodes with Even-Valued Grandparent
+ * https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/
+ * Difficulty: Medium
+ *
+ * Given the root of a binary tree, return the sum of values of nodes with an even-valued
+ * grandparent. If there are no nodes with an even-valued grandparent, return 0.
+ *
+ * A grandparent of a node is the parent of its parent if it exists.
+ */
+
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var sumEvenGrandparent = function(root) {
+  let result = 0;
+  exploreTree(root, null, null);
+  return result;
+
+  function exploreTree(current, parent, grandparent) {
+    if (!current) return;
+
+    if (grandparent?.val % 2 === 0) {
+      result += current.val;
+    }
+
+    exploreTree(current.left, current, parent);
+    exploreTree(current.right, current, parent);
+  }
+};