2020 Day 10 Complete!

2020/day10/main.go

@@ -54,11 +54,11 @@ func part1(inp []int) map[int]int {
 }
 
 var prevs map[int][]int
-var psbs map[int][][]int
+var psbs map[int]int
 
 func part2(inp []int) int {
-	psbs = make(map[int][][]int)
-	psbs[0] = [][]int{{0}}
+	psbs = make(map[int]int)
+	psbs[0] = 1
 	prevs = make(map[int][]int)
 	var phone int
 	for i := range inp {
@@ -75,24 +75,16 @@ func part2(inp []int) int {
 		prevs[inp[i]] = findPrevPoss(inp[i], inp)
 	}
 
-	total := len(findConfigs(phone))
-	return total
+	return findConfigs(phone)
 }
 
-func findConfigs(curr int) [][]int {
+func findConfigs(curr int) int {
 	if p, ok := psbs[curr]; ok {
 		return p
 	} else {
-		var ret [][]int
+		var ret int
 		for _, v := range prevs[curr] {
-			rec := findConfigs(v)
-			if len(rec) > 0 {
-				for _, rv := range rec {
-					ret = append(ret, append([]int{curr}, rv...))
-				}
-			} else {
-				ret = [][]int{{curr}}
-			}
+			ret = ret + findConfigs(v)
 		}
 		psbs[curr] = ret
 		return ret