[Leetcode - Easy] Path sum

bangdori/Path Sum.js

@@ -0,0 +1,28 @@
+/**
+ * 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) {
+  let answer = false;
+
+  const dfs = (tree, curr) => {
+    if (tree.left) dfs(tree.left, curr + tree.left.val);
+    if (tree.right) dfs(tree.right, curr + tree.right.val);
+    if (!tree.left && !tree.right && curr === targetSum) {
+      answer = true;
+      return;
+    }
+  };
+
+  if (root) dfs(root, root.val);
+  return answer;
+};