2018 Day 22 Complete

2018/day22/priorityqueue.go

@@ -0,0 +1,48 @@
+package main
+
+type Item struct {
+	pos   coord
+	equip int
+	time  int
+	index int
+}
+
+type PriorityQueue []*Item
+
+func (pq PriorityQueue) Len() int {
+	return len(pq)
+}
+
+func (pq PriorityQueue) Less(i, j int) bool {
+	return pq[i].time < pq[j].time
+}
+
+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 interface{}) {
+	item := x.(*Item)
+	item.index = len(*pq)
+	*pq = append(*pq, item)
+}
+
+func (pq *PriorityQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	item := old[n-1]
+	*pq = old[0 : n-1]
+	return item
+}
+
+func (i Item) Compare(o Item) int {
+	switch {
+	case i.time > o.time:
+		return 1
+	case i.time < o.time:
+		return -1
+	}
+	return 0
+}