Add solution #112

Author: JoshCrozier

README.md

@@ -44,6 +44,7 @@
 102|[Binary Tree Level Order Traversal](./0102-binary-tree-level-order-traversal.js)|Medium|
 104|[Maximum Depth of Binary Tree](./0104-maximum-depth-of-binary-tree.js)|Easy|
 111|[Minimum Depth of Binary Tree](./0111-minimum-depth-of-binary-tree.js)|Easy|
+112|[Path Sum](./0112-path-sum.js)|Easy|
 118|[Pascal's Triangle](./0118-pascals-triangle.js)|Easy|
 119|[Pascal's Triangle II](./0119-pascals-triangle-ii.js)|Easy|
 121|[Best Time to Buy and Sell Stock](./0121-best-time-to-buy-and-sell-stock.js)|Easy|

solutions/0112-path-sum.js

@@ -0,0 +1,44 @@
+/**
+ * 112. Path Sum
+ * https://leetcode.com/problems/path-sum/
+ * Difficulty: Easy
+ *
+ * Given the root of a binary tree and an integer targetSum, return true if the
+ * tree has a root-to-leaf path such that adding up all the values along the
+ * path equals targetSum.
+ *
+ * A leaf is a node with no children.
+ */
+
+/**
+ * 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
+ * @param {number} targetSum
+ * @return {boolean}
+ */
+var hasPathSum = function(root, targetSum) {
+  if (!root) {
+    return false;
+  }
+  const result = [];
+
+  traverse(result, root);
+
+  return result.includes(targetSum);
+};
+
+function traverse(result, node, sum = 0) {
+  if (!node.left && !node.right) {
+    result.push(sum + node.val);
+  }
+
+  if (node.left) traverse(result, node.left, sum + node.val);
+  if (node.right) traverse(result, node.right, sum + node.val);
+}