internal/priorityqueue: Actually just make our own priority queue

1 files changed, 23 insertions, 0 deletions

diff --git a/internal/priorityqueue/sift_down.go b/internal/priorityqueue/sift_down.go
new file mode 100644
index 00000000..83e3fd40
--- /dev/null
+++ b/internal/priorityqueue/sift_down.go
@@ -0,0 +1,23 @@
+package priorityqueue
+
+func (queue *Queue[T]) siftDown(idx int) {
+	for {
+		left := idx*2 + 1
+		if left >= len(queue.items) {
+			return
+		}
+
+		best := left
+		right := left + 1
+		if right < len(queue.items) && queue.less(queue.items[right], queue.items[left]) {
+			best = right
+		}
+
+		if !queue.less(queue.items[best], queue.items[idx]) {
+			return
+		}
+
+		queue.items[idx], queue.items[best] = queue.items[best], queue.items[idx]
+		idx = best
+	}
+}