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slidingwindow.go
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/
slidingwindow.go
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package slidingwindow
import (
"errors"
"fmt"
)
// Element is a wrapper
// TODO make it a linked list maybe?
type Element interface{}
// SlidingWindow represents a sliding window structure.
type SlidingWindow struct {
size int
index int
len int
queue []Element
}
// New returns an empty sliding window.
func New(size int) (*SlidingWindow, error) {
if size <= 0 {
return nil, errors.New("Size must be > 0")
}
mw := SlidingWindow{}
mw.size = size
mw.queue = make([]Element, mw.size)
mw.index = 0
return &mw, nil
}
// Add adds an element to the sliding window.
func (mw *SlidingWindow) Add(elem Element) {
mw.queue[mw.index] = elem
mw.index++
if mw.index == mw.size {
mw.index = 0
}
if mw.len < mw.size {
mw.len++
}
}
func (mw *SlidingWindow) start() int {
return (mw.index - mw.len + mw.size) % mw.size
}
// Contains returns true if elem is contained in the sliding window, false
// otherwise.
func (mw *SlidingWindow) Contains(elem Element) bool {
for i := mw.start(); i < mw.start()+mw.len; i++ {
if mw.queue[i%mw.size] == elem {
return true
}
}
return false
}
// String returns a string representing the sliding window
func (mw *SlidingWindow) String() string {
if mw.len == 0 {
return "[]"
}
s := "["
for i := mw.start(); i < mw.start()+mw.len; i++ {
s += fmt.Sprint(mw.queue[i%mw.size], " ")
}
s = s[:len(s)-1]
s += fmt.Sprint("]")
return s
}
// Len returns the length of the sliding window.
func (mw *SlidingWindow) Len() int {
return mw.len
}