feat: 100. Same Tree

Author: gwbaik9717

same-tree/gwbaik9717.js

@@ -0,0 +1,62 @@
+// n: number of nodes
+// Time complexity: O(n)
+// Space complexity: O(n)
+
+/**
+ * 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}
+ */
+var isSameTree = function (p, q) {
+  const dfs = (currentP, currentQ) => {
+    if (currentP.val !== currentQ.val) {
+      return false;
+    }
+
+    if (
+      (currentP.left && !currentQ.left) ||
+      (!currentP.left && currentQ.left)
+    ) {
+      return false;
+    }
+
+    if (
+      (currentP.right && !currentQ.right) ||
+      (!currentP.right && currentQ.right)
+    ) {
+      return false;
+    }
+
+    if (currentP.left && currentQ.left) {
+      if (!dfs(currentP.left, currentQ.left)) {
+        return false;
+      }
+    }
+
+    if (currentP.right && currentQ.right) {
+      if (!dfs(currentP.right, currentQ.right)) {
+        return false;
+      }
+    }
+
+    return true;
+  };
+
+  if ((p && !q) || (!p && q)) {
+    return false;
+  }
+
+  if (p && q) {
+    return dfs(p, q);
+  }
+
+  return true;
+};