adventofcode/src/main/java/AoC2016_11.java at main · pareronia/adventofcode · GitHub

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import static com.github.pareronia.aoc.AssertUtils.unreachable;

import static com.github.pareronia.aoc.itertools.IterTools.combinations;

import static java.util.Collections.emptyList;

import static java.util.stream.Collectors.groupingBy;

import static java.util.stream.Collectors.toList;

import java.util.ArrayDeque;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Deque;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Objects;

import java.util.Set;

import com.github.pareronia.aoc.StringUtils;

import com.github.pareronia.aoc.solution.Sample;

import com.github.pareronia.aoc.solution.Samples;

import com.github.pareronia.aoc.solution.SolutionBase;

public final class AoC2016_11

extends SolutionBase<AoC2016_11.State, Integer, Integer> {

private AoC2016_11(final boolean debug) {

super(debug);

}

public static AoC2016_11 create() {

return new AoC2016_11(false);

}

public static AoC2016_11 createDebug() {

return new AoC2016_11(true);

}

@Override

protected State parseInput(final List<String> inputs) {

return State.fromInput(inputs);

}

private int solve(final State initialState) {

final Deque<Step> steps = new ArrayDeque<>();

steps.add(Step.of(0, initialState));

final Set<Integer> seen = new HashSet<>();

seen.add(initialState.equivalentState());

while (!steps.isEmpty()) {

final Step step = steps.poll();

final State state = step.state;

if (state.isDestination()) {

log("#steps: " + step.numberOfSteps);

return step.numberOfSteps;

}

state.moves().stream()

.filter(m -> !seen.contains(m.equivalentState()))

.forEach(m -> {

seen.add(m.equivalentState());

steps.add(Step.of(step.numberOfSteps + 1, m));

});

}

throw unreachable();

}

@Override

public Integer solvePart1(final State initialState) {

return solve(initialState);

}

@Override

public Integer solvePart2(final State initialState) {

final Map<String, Integer> chips = new HashMap<>(initialState.getChips());

chips.put("elerium", 1);

chips.put("dilithium", 1);

final Map<String, Integer> gennys = new HashMap<>(initialState.getGennys());

gennys.put("elerium", 1);

gennys.put("dilithium", 1);

return solve(initialState.withChips(chips).withGennys(gennys));

}

@Samples({

@Sample(method = "part1", input = TEST, expected = "11")

})

public static void main(final String[] args) throws Exception {

AoC2016_11.create().run();

}

private static final String TEST = """

The first floor contains a hydrogen-compatible microchip, and a lithium-compatible microchip.

The second floor contains a hydrogen generator.

The third floor contains a lithium generator.

The fourth floor contains nothing relevant.

""";

static final class State {

private static final List<Integer> FLOORS = List.of(1, 2, 3, 4);

private static final int TOP = FLOORS.stream().mapToInt(Integer::intValue).max().getAsInt();

private static final int BOTTOM = FLOORS.stream().mapToInt(Integer::intValue).min().getAsInt();

private static final int MAX_ITEMS_PER_MOVE = 2;

private final Integer elevator;

private final Map<String, Integer> chips;

private final Map<String, Integer> gennys;

private final Map<Integer, List<String>> chipsPerFloor;

private final Map<Integer, List<String>> gennysPerFloor;

private State(

final Integer elevator,

final Map<String, Integer> chips,

final Map<String, Integer> gennys,

final Map<Integer, List<String>> chipsPerFloor,

final Map<Integer, List<String>> gennysPerFloor

) {

this.elevator = elevator;

this.chips = chips;

this.gennys = gennys;

this.chipsPerFloor = chips.keySet().stream().collect(groupingBy(chips::get));

this.gennysPerFloor = gennys.keySet().stream().collect(groupingBy(gennys::get));

}

State(

final Integer elevator,

final Map<String, Integer> chips,

final Map<String, Integer> gennys

) {

this( elevator,

Collections.unmodifiableMap(chips),

Collections.unmodifiableMap(gennys),

null, null);

}

public static State fromInput(final List<String> inputs) {

final Map<String, Integer> chips = new HashMap<>();

final Map<String, Integer> generators = new HashMap<>();

for (int i = 0; i < inputs.size(); i++) {

String floor = inputs.get(i);

floor = floor.replaceAll(",? and", ",");

floor = floor.replace(".", "");

final String contains = floor.split(" contains ")[1];

final String[] contained = contains.split(", ");

for (final String containee : contained) {

final String[] s = containee.split(" ");

if ("nothing".equals(s[0])) {

continue;

} else if ("generator".equals(s[2])) {

generators.put(s[1], i + 1);

} else {

chips.put(StringUtils.substringBefore(s[1], "-"), i + 1);

}

return new State(1, chips, generators);

}

public Map<String, Integer> getChips() {

return chips;

}

public Map<String, Integer> getGennys() {

return gennys;

}

boolean isSafe() {

for (final Entry<String, Integer> chip : this.chips.entrySet()) {

final List<String> gennysOnSameFloor

= this.gennysPerFloor.get(chip.getValue());

if (gennysOnSameFloor != null

&& !gennysOnSameFloor.contains(chip.getKey())) {

return false;

}

return true;

}

public boolean isDestination() {

return this.elevator == TOP

&& this.chips.values().stream().allMatch(c -> c == TOP)

&& this.gennys.values().stream().allMatch(g -> g == TOP);

}

public Integer equivalentState() {

assert this.isSafe();

final StringBuilder eq = new StringBuilder();

eq.append(this.elevator);

for (final int f : FLOORS) {

eq.append(this.chipsPerFloor.getOrDefault(f, emptyList()).size());

eq.append(this.gennysPerFloor.getOrDefault(f, emptyList()).size());

}

return Integer.valueOf(eq.toString());

}

public List<State> moves() {

final List<State> states = new ArrayList<>();

final Integer floor = this.elevator;

final List<String> chipsOnFloor

= this.chipsPerFloor.getOrDefault(floor, emptyList());

final List<String> gennysOnFloor

= this.gennysPerFloor.getOrDefault(floor, emptyList());

states.addAll(moveMultipleChips(floor, chipsOnFloor));

states.addAll(moveSingleChips(floor, chipsOnFloor));

states.addAll(moveMultipleGennys(floor, gennysOnFloor));

states.addAll(moveSingleGennys(floor, gennysOnFloor));

states.addAll(moveChipAndGennyPairs(floor, chipsOnFloor, gennysOnFloor));

return states.stream()

.filter(s -> FLOORS.contains(s.elevator))

.filter(State::isSafe)

.collect(toList());

}

private List<State> moveMultipleChips(

final Integer floor,

final List<String> chipsOnFloor) {

final List<State> states = new ArrayList<>();

if (chipsOnFloor.size() >= MAX_ITEMS_PER_MOVE) {

combinations(chipsOnFloor.size(), MAX_ITEMS_PER_MOVE).stream()

.forEach(c -> {

final List<String> chipsToMove = Arrays.stream(c)

.mapToObj(chipsOnFloor::get).collect(toList());

states.add(moveUpWithChips(chipsToMove));

if (!floorsBelowEmpty(floor)) {

states.add(moveDownWithChips(chipsToMove));

}

});

}

return states;

}

private List<State> moveSingleChips(

final Integer floor,

final List<String> chipsOnFloor) {

final List<State> states = new ArrayList<>();

for (final String chip : chipsOnFloor) {

states.add(moveUpWithChips(List.of(chip)));

if (!floorsBelowEmpty(floor)) {

states.add(moveDownWithChips(List.of(chip)));

}

return states;

}

private List<State> moveMultipleGennys(

final Integer floor,

final List<String> gennysOnFloor) {

final List<State> states = new ArrayList<>();

if (gennysOnFloor.size() >= MAX_ITEMS_PER_MOVE) {

combinations(gennysOnFloor.size(), MAX_ITEMS_PER_MOVE).stream()

.forEach(c -> {

final List<String> gennysToMove = Arrays.stream(c)

.mapToObj(gennysOnFloor::get).collect(toList());

states.add(moveUpWitGennys(gennysToMove));

if (!floorsBelowEmpty(floor)) {

states.add(moveDownWithGennys(gennysToMove));

}

});

}

return states;

}

private List<State> moveSingleGennys(

final Integer floor,

final List<String> gennysOnFloor) {

final List<State> states = new ArrayList<>();

for (final String genny : gennysOnFloor) {

states.add(moveUpWitGennys(List.of(genny)));

if (!floorsBelowEmpty(floor)) {

states.add(moveDownWithGennys(List.of(genny)));

}

return states;

}

private List<State> moveChipAndGennyPairs(

final Integer floor,

final List<String> chipsOnFloor,

final List<String> gennysOnFloor) {

final List<State> states = new ArrayList<>();

final List<String> intersection = new ArrayList<>(chipsOnFloor);

intersection.retainAll(gennysOnFloor);

for (final String match : intersection) {

states.add(withChipsTo(List.of(match), floor + 1)

.withGennysTo(List.of(match), floor + 1)

.withElevator(floor + 1));

if (!floorsBelowEmpty(floor)) {

states.add(withChipsTo(List.of(match), floor - 1)

.withGennysTo(List.of(match), floor - 1)

.withElevator(floor - 1));

}

return states;

}

private State withElevator(final int elevator) {

return new State(elevator, this.chips, this.gennys);

}

private State withChips(final Map<String, Integer> chips) {

return new State(this.elevator, chips, this.gennys);

}

private State withGennys(final Map<String, Integer> gennys) {

return new State(this.elevator, this.chips, gennys);

}

private State moveUpWithChips(final List<String> chips) {

return withChipsTo(chips, this.elevator + 1)

.withElevator(this.elevator + 1);

}

private State moveUpWitGennys(final List<String> gennys) {

return withGennysTo(gennys, this.elevator + 1)

.withElevator(this.elevator + 1);

}

private State moveDownWithChips(final List<String> chips) {

return withChipsTo(chips, this.elevator - 1)

.withElevator(this.elevator - 1);

}

private State moveDownWithGennys(final List<String> gennys) {

return withGennysTo(gennys, this.elevator - 1)

.withElevator(this.elevator - 1);

}

private State withChipsTo(final List<String> chips, final Integer floor) {

final Map<String, Integer> newChips = new HashMap<>(this.chips);

chips.forEach(c -> newChips.put(c, floor));

return this.withChips(newChips);

}

private State withGennysTo(final List<String> generators, final Integer floor) {

final Map<String, Integer> newGenerators = new HashMap<>(this.gennys);

generators.forEach(g -> newGenerators.put(g, floor));

return this.withGennys(newGenerators);

}

private boolean floorsBelowEmpty(final Integer floor) {

for (int f = floor; f > BOTTOM; f--) {

if (this.chipsPerFloor.get(f - 1) != null) {

return false;

}

if (this.gennysPerFloor.get(f - 1) != null) {

return false;

}

return true;

}

@Override

public boolean equals(final Object obj) {

if (this == obj) {

return true;

}

if (obj == null) {

return false;

}

if (getClass() != obj.getClass()) {

return false;

}

final State other = (State) obj;

return Objects.equals(elevator, other.elevator)

&& Objects.equals(chips, other.chips)

&& Objects.equals(gennys, other.gennys);

}

@Override

public int hashCode() {

return Objects.hash(chips, elevator, gennys);

}

@Override

public String toString() {

final StringBuilder builder = new StringBuilder();

builder.append("State [elevator=").append(elevator)

.append(", chips=").append(chips)

.append(", gennys=").append(gennys)

.append(", isSafe=").append(isSafe()).append("]");

return builder.toString();

}

record Step(int numberOfSteps, State state) {;

public static Step of(final int numberOfSteps, final State state) {

return new Step(numberOfSteps, state);

}

adventofcode/src/main/java/AoC2016_11.java at main · pareronia/adventofcode · GitHub

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