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nove to "index" naming

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This commit is contained in:
Gregory 2022-01-03 01:19:45 +02:00
parent afc077c8a6
commit 1b3ca7b515
2 changed files with 41 additions and 41 deletions
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52
sorting/priority_queue/index_priority_queue.go
View file

@ -1,13 +1,13 @@
package priority_queue
type IndexPriorityQueue[T any] interface {
top() T // get item with biggest priority
topKey() int // get key of an item with biggest priority
remove() T // removes item with the biggest priority
removeKey(key int) T // removes item with specified key
insert(key int, item T) // adds item with specified key
change(key int, item T) // changes item with specified key
contains(key int) bool // checks if key exists in queue
top() T // get item with biggest priority
topIndex() int // get index of an item with biggest priority
remove() T // removes item with the biggest priority
removeAtIndex(index int) T // removes item at specified index
insert(index int, item T) // adds item at specified index
change(index int, item T) // changes item at specified index and preserves ordering
contains(index int) bool // checks if item exists at specified index
isEmpty() bool
size() int
}
@ -15,13 +15,13 @@ type IndexPriorityQueue[T any] interface {
type indexPriorityQueue[T any] struct {
n int
// unordered items.
// items[key] = item
// items[index] = item
items []T
// priority queue. Contains keys for items in priority order.
// items[pq[1]] = item with biggest priority
pq []int
// "reverse" for pq. Maps item key to priority
// qp[key] = priority index, qp[pq[key]] = pq[qp[key]] = key
// "reverse" for pq. Maps item index to priority
// qp[index] = priority index, qp[pq[index]] = pq[qp[index]] = index
qp []int
// "less" function. Depending on desired order first element
// not necessary less than a second
@ -51,39 +51,39 @@ func (q *indexPriorityQueue[T]) top() T {
return q.items[q.pq[0]]
}
func (q *indexPriorityQueue[T]) topKey() int {
func (q *indexPriorityQueue[T]) topIndex() int {
return q.pq[0]
}
func (q *indexPriorityQueue[T]) insert(key int, item T) {
q.pq[q.n] = key
q.qp[key] = q.n
q.items[key] = item
func (q *indexPriorityQueue[T]) insert(index int, item T) {
q.pq[q.n] = index
q.qp[index] = q.n
q.items[index] = item
q.swim(q.n)
q.n++
}
func (q *indexPriorityQueue[T]) remove() T {
return q.removeKey(q.topKey())
return q.removeAtIndex(q.topIndex())
}
func (q *indexPriorityQueue[T]) removeKey(key int) T {
pivot := q.qp[key]
func (q *indexPriorityQueue[T]) removeAtIndex(index int) T {
pivot := q.qp[index]
q.n--
q.swap(pivot, q.n)
q.swim(pivot)
q.sink(pivot)
// TODO: need to remove actual item from items array
// to prevent memory leak
q.qp[key] = -1
q.qp[index] = -1
q.pq[q.n] = -1
return q.items[key]
return q.items[index]
}
func (q *indexPriorityQueue[T]) change(key int, item T) {
q.items[key] = item
q.swim(q.qp[key])
q.sink(q.qp[key])
func (q *indexPriorityQueue[T]) change(index int, item T) {
q.items[index] = item
q.swim(q.qp[index])
q.sink(q.qp[index])
}
func (pq *indexPriorityQueue[_]) size() int {
@ -94,8 +94,8 @@ func (pq *indexPriorityQueue[_]) isEmpty() bool {
return pq.n == 0
}
func (q *indexPriorityQueue[_]) contains(key int) bool {
return q.qp[key] != -1
func (q *indexPriorityQueue[_]) contains(index int) bool {
return q.qp[index] != -1
}
func (q *indexPriorityQueue[T]) sink(parent int) {

30
sorting/priority_queue/index_priority_queue_test.go
View file

@ -14,7 +14,7 @@ func TestNewIPQ(t *testing.T) {
assert.Equal(t, 0, q.size())
assert.Equal(t, true, q.isEmpty())
assert.Equal(t, -1, q.topKey())
assert.Equal(t, -1, q.topIndex())
// TODO: maybe should return nil?
// assert.Equal(t, 0, q.top())
}
@ -40,7 +40,7 @@ func TestMoreIPQInsert(t *testing.T) {
pq.insert(1, 10)
assert.Equal(t, 1, pq.topKey())
assert.Equal(t, 1, pq.topIndex())
assert.Equal(t, 10, pq.top())
assert.Equal(t, 1, pq.size())
assert.Equal(t, true, pq.contains(1))
@ -48,7 +48,7 @@ func TestMoreIPQInsert(t *testing.T) {
pq.insert(2, 20)
assert.Equal(t, 2, pq.topKey())
assert.Equal(t, 2, pq.topIndex())
assert.Equal(t, 20, pq.top())
assert.Equal(t, 2, pq.size())
assert.Equal(t, true, pq.contains(2))
@ -60,7 +60,7 @@ func TestIPQRemove(t *testing.T) {
pq.insert(1, 10)
assert.Equal(t, 1, pq.topKey())
assert.Equal(t, 1, pq.topIndex())
assert.Equal(t, 10, pq.top())
assert.Equal(t, 1, pq.size())
assert.Equal(t, true, pq.contains(1))
@ -68,7 +68,7 @@ func TestIPQRemove(t *testing.T) {
pq.insert(2, 20)
assert.Equal(t, 2, pq.topKey())
assert.Equal(t, 2, pq.topIndex())
assert.Equal(t, 20, pq.top())
assert.Equal(t, 2, pq.size())
assert.Equal(t, true, pq.contains(2))
@ -103,36 +103,36 @@ func TestIPQRemoveAtIndex(t *testing.T) {
pq.insert(4, 40)
assert.Equal(t, 40, pq.top())
assert.Equal(t, 4, pq.topKey())
assert.Equal(t, 4, pq.topIndex())
// top -> 40 - 30 - 10
removed := pq.removeKey(5)
removed := pq.removeAtIndex(5)
assert.Equal(t, 20, removed)
assert.Equal(t, 40, pq.top())
assert.Equal(t, 4, pq.topKey())
assert.Equal(t, 4, pq.topIndex())
// top -> 30 - 10
removed = pq.removeKey(4)
removed = pq.removeAtIndex(4)
assert.Equal(t, 40, removed)
assert.Equal(t, 30, pq.top())
assert.Equal(t, 3, pq.topKey())
assert.Equal(t, 3, pq.topIndex())
// top -> 30 - 20 - 10
pq.insert(5, 20)
assert.Equal(t, 30, pq.top())
assert.Equal(t, 3, pq.topKey())
assert.Equal(t, 3, pq.topIndex())
// top -> 10
removed = pq.removeKey(3)
removed = pq.removeAtIndex(3)
assert.Equal(t, 30, removed)
removed = pq.removeKey(5)
removed = pq.removeAtIndex(5)
assert.Equal(t, 20, removed)
assert.Equal(t, 10, pq.top())
assert.Equal(t, 8, pq.topKey())
assert.Equal(t, 8, pq.topIndex())
assert.Equal(t, 1, pq.size())
assert.Equal(t, false, pq.contains(5))
assert.Equal(t, false, pq.contains(4))
@ -179,7 +179,7 @@ func TestMultiwayMerge(t *testing.T) {
for !pq.isEmpty() {
actual += string(pq.top())
streamIndex := pq.topKey()
streamIndex := pq.topIndex()
pq.remove()
rune, _, err := allStreams[streamIndex].ReadRune()
if err != io.EOF {