planner

cmd/planner/prio-queue.go

@@ -0,0 +1,36 @@
+package main
+
+import "time"
+
+type pqItem struct {
+	Stop  string
+	Cost  time.Time
+	index int
+}
+
+type priorityQueue []*pqItem
+
+func (pq priorityQueue) Len() int { return len(pq) }
+
+func (pq priorityQueue) Less(i, j int) bool { return pq[i].Cost.Before(pq[j].Cost) }
+
+func (pq priorityQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *priorityQueue) Push(x any) {
+	item := x.(*pqItem)
+	item.index = len(*pq)
+	*pq = append(*pq, item)
+}
+
+func (pq *priorityQueue) Pop() any {
+	old := *pq
+	n := len(old)
+	item := old[n-1]
+	item.index = -1
+	*pq = old[:n-1]
+	return item
+}