From ce767c333de5f6d25ca8e3740ddf1faed46728e8 Mon Sep 17 00:00:00 2001
From: Emir Pasic <emirpasic@hotmail.com>
Date: Thu, 5 Mar 2015 22:37:25 +0100
Subject: [PATCH] add Clear() method to stack interface

---
 stacks/arraystack/arraystack.go           | 6 ++++++
 stacks/linkedliststack/linkedliststack.go | 6 ++++++
 stacks/stacks.go                          | 1 +
 3 files changed, 13 insertions(+)

diff --git a/stacks/arraystack/arraystack.go b/stacks/arraystack/arraystack.go
index 8034731..63107f4 100644
--- a/stacks/arraystack/arraystack.go
+++ b/stacks/arraystack/arraystack.go
@@ -88,6 +88,12 @@ func (stack *Stack) Size() int {
 	return stack.top + 1
 }
 
+// Removes all elements from the stack.
+func (stack *Stack) Clear() {
+	stack.top = -1
+	stack.items = []interface{}{}
+}
+
 func (stack *Stack) String() string {
 	str := "ArrayStack\n"
 	values := []string{}
diff --git a/stacks/linkedliststack/linkedliststack.go b/stacks/linkedliststack/linkedliststack.go
index c1571d9..f3b1762 100644
--- a/stacks/linkedliststack/linkedliststack.go
+++ b/stacks/linkedliststack/linkedliststack.go
@@ -84,6 +84,12 @@ func (stack *Stack) Size() int {
 	return stack.size
 }
 
+// Removes all elements from the stack.
+func (stack *Stack) Clear() {
+	stack.top = nil
+	stack.size = 0
+}
+
 func (stack *Stack) String() string {
 	str := "LinkedListStack\n"
 	element := stack.top
diff --git a/stacks/stacks.go b/stacks/stacks.go
index d55d03e..2c78aea 100644
--- a/stacks/stacks.go
+++ b/stacks/stacks.go
@@ -24,4 +24,5 @@ type Interface interface {
 	Peek() (value interface{}, ok bool)
 	Empty() bool
 	Size() int
+	Clear()
 }