package day17

import (
	"sort"
	"tools"
)

func getCombinations(containers []int, sum int) (combinations [][]int) {
	for i, c := range containers {
		if c > sum {
			break
		} else if c == sum {
			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+1:], sum-c)
		for _, v := range subCombinations {
			subCombination := append([]int{c}, v...)
			combinations = append(combinations, subCombination)
		}
	}
	return combinations
}

func Part1(puzzle tools.AoCPuzzle) interface{} {
	input := puzzle.GetInputArrayInt()
	sort.Ints(input)

	combos150 := getCombinations(input, 150)

	return len(combos150)
}

func Part2(puzzle tools.AoCPuzzle) interface{} {
	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]
}