50 lines
793 B
Go
50 lines
793 B
Go
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package util
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type (
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Stack struct {
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top *StackNode
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length int
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}
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StackNode struct {
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value interface{}
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prev *StackNode
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}
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)
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// Create a new Stack
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func NewStack() *Stack {
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return &Stack{nil, 0}
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}
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// Return the number of items in the Stack
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func (this *Stack) Len() int {
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return this.length
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}
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// View the top item on the Stack
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func (this *Stack) Peek() interface{} {
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if this.length == 0 {
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return nil
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}
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return this.top.value
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}
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// Pop the top item of the Stack and return it
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func (this *Stack) Pop() interface{} {
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if this.length == 0 {
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return nil
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}
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n := this.top
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this.top = n.prev
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this.length--
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return n.value
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}
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// Push a value onto the top of the Stack
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func (this *Stack) Push(value interface{}) {
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n := &StackNode{value, this.top}
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this.top = n
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this.length++
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}
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