aoc2015/day17/day.go
Stefan Harmuth a0415caa4a day17 solved
2020-12-29 10:36:17 +01:00

57 lines
1.3 KiB
Go

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]
}