From a0415caa4ace61ab8e8dcd17d1e3416703da41e7 Mon Sep 17 00:00:00 2001
From: Stefan Harmuth <stefan.harmuth@net-m.de>
Date: Tue, 29 Dec 2020 10:36:17 +0100
Subject: [PATCH] day17 solved

---
 day17/day.go | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/day17/day.go b/day17/day.go
index ed0c308..daf999e 100644
--- a/day17/day.go
+++ b/day17/day.go
@@ -1,7 +1,6 @@
 package day17
 
 import (
-	"fmt"
 	"sort"
 	"tools"
 )
@@ -11,11 +10,14 @@ func getCombinations(containers []int, sum int) (combinations [][]int) {
 		if c > sum {
 			break
 		} else if c == sum {
-			return [][]int{{c}}
+			combinations = append(combinations, []int{c})
+			if i == len(containers)-1 || containers[i+1] != sum {
+				return combinations
+			}
 		} else if i == len(containers)-1 {
 			break
 		}
-		subCombinations := getCombinations(containers[i:], sum-c)
+		subCombinations := getCombinations(containers[i+1:], sum-c)
 		for _, v := range subCombinations {
 			subCombination := append([]int{c}, v...)
 			combinations = append(combinations, subCombination)
@@ -28,13 +30,27 @@ func Part1(puzzle tools.AoCPuzzle) interface{} {
 	input := puzzle.GetInputArrayInt()
 	sort.Ints(input)
 
-	combos25 := getCombinations(input, 25)
-	fmt.Println(combos25)
-	//combos150 := getCombinations(input, 150)
+	combos150 := getCombinations(input, 150)
 
-	return len(combos25)
+	return len(combos150)
 }
 
 func Part2(puzzle tools.AoCPuzzle) interface{} {
-	return 0
+	input := puzzle.GetInputArrayInt()
+	sort.Ints(input)
+
+	// REVISIT! This does not account for the fact, that a container might be re-used
+	// Still, the answer is correct for the given input.
+
+	combos150 := getCombinations(input, 150)
+	minNumContainers := len(input)
+	numContainers := make(map[int]int)
+	for _, v := range combos150 {
+		numContainers[len(v)]++
+		if len(v) < minNumContainers {
+			minNumContainers = len(v)
+		}
+	}
+
+	return numContainers[minNumContainers]
 }