add 100 leetcode easy

Author: betomoedano

binary-trees/100-same-tree.js

@@ -0,0 +1,41 @@
+/**
+ * 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} p
+ * @param {TreeNode} q
+ * @return {boolean}
+ * Time O(N)
+ * Space O(N)
+ * Both solutions run in the same time-space complexity
+ */
+
+// iterative solution
+var isSameTree = function (p, q) {
+  const stack = [[p, q]];
+
+  while (stack.length > 0) {
+    const [p, q] = stack.pop();
+
+    if (p === null && q === null) continue;
+    if (p === null || q === null) return false;
+    if (p.val !== q.val) return false;
+    stack.push([p.left, q.left]);
+    stack.push([p.right, q.right]);
+  }
+  return true;
+};
+
+// recursive solution
+// function isSameHelper(tree1, tree2) {
+//   if (tree1 === null && tree2 === null) return true;
+//   if (tree2 === null || tree2 === null) return false;
+//   if (tree1.val !== tree2.val) return false;
+
+//   return isSameHelper(tree1.left, tree2.left) && isSameHelper(tree1.right, tree2.right);
+// }