add new solutions

solutions/1/q101/solution.go

@@ -0,0 +1,27 @@
+package q101
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func traverse(left, right *TreeNode) bool {
+	if left == nil && right == nil {
+		return true
+	}
+	if left == nil || right == nil {
+		return false
+	}
+	if left.Val != right.Val {
+		return false
+	}
+	return traverse(left.Left, right.Right) &&
+		traverse(left.Right, right.Left)
+}
+
+func isSymmetric(root *TreeNode) bool {
+	return traverse(root.Left, root.Right)
+}
+
+var _ = isSymmetric