refactor

1 files changed, 16 insertions, 0 deletions

diff --git a/stack.go b/stack.go
new file mode 100644
index 0000000..182d418
--- /dev/null
+++ b/stack.go
@@ -0,0 +1,16 @@
+package main
+
+type Stack []float64
+
+func (s *Stack) push(v float64) {
+	*s = append(*s, v)
+}
+
+func (s *Stack) pop() *float64 {
+	if len(*s) > 0 {
+		v := (*s)[len(*s)-1]
+		*s = (*s)[:len(*s)-1]
+		return &v
+	}
+	return nil
+}