collections/stack added

collections/stack/stack.go

@@ -0,0 +1,61 @@
+package stack
+
+type Stack struct {
+	st []interface{}
+    len int
+}
+
+func New() *Stack {
+	stack := &Stack{}
+	stack.st = make([]interface{}, 1)
+    stack.len = 0
+    return stack
+}
+
+func (stack *Stack) Length() int {
+	return stack.len
+}
+
+func (stack *Stack) Pop() {
+	stack.st = stack.st[1:]
+	stack.len -= 1
+}
+
+func (stack *Stack) Peek() interface{} {
+    return stack.st[0]
+}
+
+func (stack *Stack) IsEmpty() bool {
+	return (stack.len == 0)
+}
+
+func (stack *Stack) Push(value interface{}) {
+	stack.len += 1
+	add(stack, value)
+} 
+
+func add(slice *Stack, value interface{}) {
+	var tmpSlice []interface{} = make([]interface{}, slice.len)
+	if slice.len == 0 {
+		slice.st[0] = value
+		return
+	}
+	
+	for i:=0; i < slice.len; i++ {
+		tmpSlice[i] = 0
+	}
+	
+	for i:=0; i < slice.len; i++ {
+		if i == 0 {
+			tmpSlice[0] = value
+		} else {
+			tmpSlice[i] = slice.st[i - 1]
+		}
+
+		if i == slice.len - 1 {
+			break
+		}
+	}
+	
+	slice.st = tmpSlice
+}

collections/stack/stack_test.go

@@ -0,0 +1,25 @@
+package stack
+
+import "testing"
+
+func Test_Stack(t *testing.T) {
+	stack := New()
+
+    stack.Push(5)
+    stack.Push(6)
+    stack.Push(7)
+	
+	if stack.Length() != 3 {
+		t.Error("[Error] stack length is wrong")
+	}
+
+    stack.Pop()
+
+	if stack.Length() != 2 {
+		t.Error("[Error] stack length is wrong after pop")
+	}
+	
+	if stack.Peek() != 6 {
+		t.Error("[Error] stack Peek is wrong")
+	}
+}