added stack-1

stack-1-introduction/stack-1-introduction.go

@@ -0,0 +1,74 @@
+// ====================================================
+// Data-Structures-with-Go Copyright(C) 2017 Furkan Türkal
+// This program comes with ABSOLUTELY NO WARRANTY; This is free software,
+// and you are welcome to redistribute it under certain conditions; See
+// file LICENSE, which is part of this source code package, for details.
+// ====================================================
+
+package main
+
+import "fmt"
+
+const MaxUint = ^uint(0)
+const MinUint = 0
+const MaxInt = int(MaxUint >> 1)
+const MinInt = -MaxInt - 1
+
+type Stack struct {
+	top      int
+	capacity uint
+	array    []int
+}
+
+//Returns an initialized list
+func (s *Stack) Init(capacity uint) *Stack {
+	s.top = -1
+	s.capacity = capacity
+	s.array = make([]int, capacity)
+	return s
+}
+
+//Returns an new list
+func New(capacity uint) *Stack {
+	return new(Stack).Init(capacity)
+}
+
+// Stack is full when top is equal to the last index
+func IsFull(stack *Stack) bool {
+	return stack.top == int(stack.capacity)-1
+}
+
+// Stack is empty when top is equal to -1
+func IsEmpty(stack *Stack) bool {
+	return stack.top == -1
+}
+
+func Push(stack *Stack, item int) {
+	if IsFull(stack) {
+		return
+	}
+	stack.top++
+	stack.array[stack.top] = item
+	fmt.Println("Pushed to stack : %d", item)
+}
+
+func Pop(stack *Stack) int {
+	if IsEmpty(stack) {
+		return MinInt
+	}
+	temp := stack.array[stack.top]
+	stack.top--
+	return temp
+}
+
+func main() {
+
+	stack := New(100)
+
+	Push(stack, 10)
+	Push(stack, 20)
+	Push(stack, 30)
+
+	fmt.Println("Popped from stack : %d", Pop(stack))
+
+}