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3 changes: 2 additions & 1 deletion exercises/practice/hangman/.meta/config.json
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,8 @@
"contributors": [
"mirkoperillo",
"msomji",
"muzimuzhi"
"muzimuzhi",
"thibault2705"
],
"files": {
"solution": [
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94 changes: 54 additions & 40 deletions exercises/practice/hangman/.meta/src/reference/java/Hangman.java
Original file line number Diff line number Diff line change
@@ -1,76 +1,90 @@
import io.reactivex.Observable;

import java.util.*;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

class Hangman {

Observable<Output> play(
Observable<String> words,
Observable<Output> guess(
String word,
Observable<String> letters) {
return Observable
.combineLatest(
words,
letters.startWith(""),
(word, letter) -> new AbstractMap.SimpleEntry<>(word, letter))
.scan(
Output.empty(),
(state, entry) -> {
System.out.println(state + " -> " + entry);
if (state == null || state.status != Status.PLAYING) {
return createNewGame(entry.getKey());
} else {
return processNewLetter(state, entry.getValue());
return letters
.startWith("")
.scan(Output.empty(), (state, letter) -> {
if (state == null || state.state == null) {
return createNewGame(word);
}

if (letter.isEmpty()) {
return state;
}

if (state.state == Status.WIN) {
throw new IllegalStateException("cannot guess after the game is won");
}

if (state.state == Status.LOSE) {
throw new IllegalStateException("cannot guess after the game is lost");
}

return processNewLetter(state, letter);
})
.skip(1); // Skip the initial state
.skip(1);
}

private static Output createNewGame(String word) {
return Output.initialState(word);
}

private static Output processNewLetter(
Output state,
String letter) {
private static Output processNewLetter(Output state, String letter) {
if (state.isLetterAlreadyPlayed(letter)) {
throw new IllegalArgumentException("Letter " + letter + " was already played");
return processIncorrectGuess(state, letter);
}

if (state.isLetterInSecret(letter)) {
return processCorrectGuess(state, letter);
} else {
return processIncorrectGuess(state, letter);
}

return processIncorrectGuess(state, letter);
}

private static Output processCorrectGuess(Output state, String letter) {
Set<String> newGuess = new HashSet<>(state.guess);
newGuess.add(letter);
String discovered = Output.getGuessedWord(state.secret, newGuess);
Status newStatus = Output.isWin(state.secret, newGuess) ? Status.WIN : Status.PLAYING;
Set<String> newGuesses = new LinkedHashSet<>(state.guesses);
newGuesses.add(letter);

String discovered = Output.getGuessedWord(state.word, newGuesses);
Status newStatus = Output.isWin(state.word, newGuesses) ? Status.WIN : Status.ON_GOING;

return new Output(
state.secret,
discovered,
newGuess,
state.misses,
state.parts,
newStatus);
state.word,
discovered,
newGuesses,
state.misses,
state.parts,
newStatus);
}

private static Output processIncorrectGuess(Output state, String letter) {
Set<String> newMisses = new HashSet<>(state.misses);
Set<String> newMisses = new LinkedHashSet<>(state.misses);
newMisses.add(letter);

List<Part> newParts = new ArrayList<>(state.parts);
newParts.add(order[newParts.size()]);
Status newStatus = Output.isLoss(newMisses) ? Status.LOSS : Status.PLAYING;
if (newParts.size() < order.length) {
newParts.add(order[newParts.size()]);
}

Status newStatus = newParts.size() >= order.length ? Status.LOSE : Status.ON_GOING;

return new Output(
state.secret,
state.discovered,
state.guess,
state.word,
state.maskedWord,
state.guesses,
newMisses,
newParts,
newStatus);
}

static Part[] order = Part.values();

}
95 changes: 50 additions & 45 deletions exercises/practice/hangman/.meta/src/reference/java/Output.java
Original file line number Diff line number Diff line change
@@ -1,89 +1,94 @@
import static java.util.stream.Collectors.joining;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

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

class Output {

public final String secret;
public final String discovered;
public final Set<String> guess;
static final int MAX_FAILURES = Part.values().length;

public final String word;
public final String maskedWord;
public final Set<String> guesses;
public final Set<String> misses;
public final List<Part> parts;
public final Status status;
public final Status state;
public final int remainingFailures;

Output(
final String secret,
final String discovered,
final Set<String> guess,
final Set<String> misses,
final List<Part> parts,
final Status status) {
this.secret = secret;
this.discovered = discovered;
this.guess = Set.copyOf(guess);
final String word,
final String maskedWord,
final Set<String> guesses,
final Set<String> misses,
final List<Part> parts,
final Status state) {
this.word = word;
this.maskedWord = maskedWord;
this.guesses = Set.copyOf(guesses);
this.misses = Set.copyOf(misses);
this.parts = List.copyOf(parts);
this.status = status;
this.state = state;
this.remainingFailures = Math.max(0, MAX_FAILURES - 1 - parts.size());
}

static Output empty() {
return new Output(
null,
null,
Collections.emptySet(),
Collections.emptySet(),
Collections.emptyList(),
null);
null,
null,
Collections.emptySet(),
Collections.emptySet(),
Collections.emptyList(),
null);
}

static Output initialState(final String secret) {
return new Output(
secret,
getGuessedWord(secret, Collections.emptySet()),
new HashSet<>(),
new HashSet<>(),
new ArrayList<>(),
Status.PLAYING);
secret,
getGuessedWord(secret, Collections.emptySet()),
new LinkedHashSet<>(),
new LinkedHashSet<>(),
new ArrayList<>(),
Status.ON_GOING);
}

boolean isLetterAlreadyPlayed(final String letter) {
return guess.contains(letter) || misses.contains(letter);
return guesses.contains(letter) || misses.contains(letter);
}

boolean isLetterInSecret(final String letter) {
return secret.contains(letter);
return word.contains(letter);
}

static String getGuessedWord(String secret, Set<String> letters) {
return secret.chars()
.mapToObj(i -> String.valueOf((char) i))
.map(c -> letters.contains(c) ? c : "_")
.collect(joining());
.mapToObj(i -> String.valueOf((char) i))
.map(c -> letters.contains(c) ? c : "_")
.collect(joining());
}

static boolean isWin(String secret, Set<String> guessedLetters) {
return secret.chars()
.mapToObj(i -> String.valueOf((char) i))
.allMatch(guessedLetters::contains);
.mapToObj(i -> String.valueOf((char) i))
.allMatch(guessedLetters::contains);
}

static boolean isLoss(Set<String> missedLetters) {
return missedLetters.size() >= Part.values().length;
static boolean isLoss(List<Part> parts) {
return parts.size() >= MAX_FAILURES;
}

@Override
public String toString() {
return "Output{" +
"secret='" + secret + '\'' +
", discovered='" + discovered + '\'' +
", guess=" + guess +
", misses=" + misses +
", parts=" + parts +
", status=" + status +
'}';
"secret='" + word + '\'' +
", discovered='" + maskedWord + '\'' +
", guess=" + guesses +
", misses=" + misses +
", parts=" + parts +
", status=" + state +
", remainingFailures=" + remainingFailures +
'}';
}
}
Original file line number Diff line number Diff line change
Expand Up @@ -4,5 +4,9 @@ enum Part {
LEFT_ARM,
RIGHT_ARM,
LEFT_LEG,
RIGHT_LEG
RIGHT_LEG,
LEFT_EYE,
RIGHT_EYE,
NOSE,
MOUTH
}
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
enum Status {
PLAYING,
ON_GOING,
WIN,
LOSS
LOSE
}
40 changes: 40 additions & 0 deletions exercises/practice/hangman/.meta/tests.toml
Original file line number Diff line number Diff line change
@@ -0,0 +1,40 @@
# This is an auto-generated file.
#
# Regenerating this file via `configlet sync` will:
# - Recreate every `description` key/value pair
# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
# - Preserve any other key/value pair
#
# As user-added comments (using the # character) will be removed when this file
# is regenerated, comments can be added via a `comment` key.

[2419ffe6-16d8-4059-856a-9a101998a418]
description = "Initially 9 failures are allowed and no letters are guessed"

[17c4296d-daab-44dc-8155-37c77caa52c1]
description = "After 10 failures the game is over"

[77c9ae1f-bbc4-4ed4-b67e-08110cbcfc17]
description = "Losing with several correct guesses"

[25101d8d-9874-405b-9825-193a14b69753]
description = "Feeding a correct letter removes underscores"

[8e6bd521-bc9b-458f-9cce-f57f4140c173]
description = "Feeding a correct letter twice counts as a failure"

[5e6971b7-5e5f-49c2-b85d-1dd6aeb53bd5]
description = "Guessing a repeated letter reveals all instances"

[a6c69d92-01ef-4b81-b9d9-801131e79bbb]
description = "Getting all the letters right makes for a win"

[2dc47994-b434-4a26-b70c-1eebeff77fe4]
description = "Winning on the last guess is still a win"

[52801d56-6963-494b-a901-5736e46ddc12]
description = "Guessing after a lose is error"

[29a874f3-a413-4e1b-9a60-6be018e70b60]
description = "Guessing after a win is error"
2 changes: 1 addition & 1 deletion exercises/practice/hangman/src/main/java/Hangman.java
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@

class Hangman {

Observable<Output> play(Observable<String> words, Observable<String> letters) {
Observable<Output> guess(String word, Observable<String> letters) {
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I think this change is because we have removed the "consecutive games" test, which isn't in the problem specifications. To me, if we are going to change the first argument from Observable to a String, then I think we should also remove the other Observable usages. letters can become a list and the return could be Output directly. This would simplify the exercise and remove the RxJava dependency. The exercise's .docs/instructions.append.md should also be deleted if we do this.

The other alternative is to keep the "consecutive games" test case and keep using RxJava. We can have Java track specific tests.

throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
}

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