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48 lines
782 B
Go
48 lines
782 B
Go
package stack
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type StackItem struct {
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item interface{}
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next *StackItem
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}
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// Stack is a base structure for LIFO
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type Stack struct {
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sp *StackItem
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depth uint64
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}
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// Initialzes new Stack
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func New() *Stack {
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var stack *Stack = new(Stack)
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stack.depth = 0
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return stack
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}
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// Pushes a given item into Stack
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func (stack *Stack) Push(item interface{}) {
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stack.sp = &StackItem{item: item, next: stack.sp}
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stack.depth++
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}
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// Deletes top of a stack and return it
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func (stack *Stack) Pop() interface{} {
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if stack.depth > 0 {
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item := stack.sp.item
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stack.sp = stack.sp.next
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stack.depth--
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return item
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}
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return nil
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}
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// Peek returns top of a stack without deletion
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func (stack *Stack) Peek() interface{} {
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if stack.depth > 0 {
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return stack.sp.item
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}
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return nil
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}
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