go 구현 스 택

package stack
//           ，   interface
type Stack struct {
    data []interface{}
}

func (s *Stack) Push (item interface{}) (string, bool) {
    s.data = append(s.data, item)
    return "ok", true
}

func (s *Stack) Pop () (interface{}, bool) {
    length := s.Length()
    var item interface{}
    if length == 0 {
        return item, false
    } else if length == 1{
        item = s.data[0]
        s.data = []interface{} {}
        return item, true
    } else {
        item = s.data[length - 1]
        s.data = s.data[0:length-2]
        return item, true
    }
}

func (s *Stack) ElementAt (index int) (interface{}, bool) {
    length := len(s.data)
    if index >= length {
        return []interface{} {}, false
    }
    return s.data[index], true
}
//     ，        
func (s *Stack) UpdateElementAt (data interface{}, index int) (bool) {
    length := len(s.data)
    if index >= length {
        return false
    }
    s.data[index] = data
    return true
}
//     ，        
func (s *Stack) RemoveElementAt (index int) (interface{}, bool) {
    length := len(s.data)
    if index >= length {
        return []interface{} {}, false
    }
    s.data = append(
        s.data[:index],
        s.data[index + 1:],
    )
    return s.data[index], true
}

func (s *Stack) Length () (int) {
    return len(s.data);
}