[LBP] 박세은 사다리 1단계 제출합니다.

build.gradle

@@ -14,6 +14,9 @@ dependencies {
     testImplementation platform('org.assertj:assertj-bom:3.25.1')
     testImplementation('org.junit.jupiter:junit-jupiter')
     testImplementation('org.assertj:assertj-core')
+    implementation 'org.slf4j:slf4j-api:2.0.9'
+    implementation 'org.slf4j:slf4j-simple:2.0.9'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.8.2'
 }
 
 test {

src/main/java/Application.java

@@ -0,0 +1,14 @@
+import model.Ladder;
+import utils.ExceptionHandler;
+import view.LadderView;
+
+public class Application {
+    public static void main(String[] args) {
+        try {
+            Ladder ladder = Ladder.of(4, 4);
+            LadderView.printLadder(ladder);
+        } catch (Exception e) {
+            ExceptionHandler.handleException(e);
+        }
+    }
+}

src/main/java/model/Ladder.java

@@ -0,0 +1,17 @@
+package model;
+
+public class Ladder {
+    private final Lines lines;
+
+    public Ladder(Lines lines) {
+        this.lines = lines;
+    }
+
+    public static Ladder of(int width, int height) {
+        return new Ladder(LadderGenerator.generate(width, height));
+    }
+
+    public Lines getLines() {
+        return lines;
+    }
+}

src/main/java/model/LadderGenerator.java

@@ -0,0 +1,7 @@
+package model;
+
+public class LadderGenerator {
+    public static Lines generate(int width, int height) {
+        return LineGenerator.generate(width, height);
+    }
+}

src/main/java/model/LadderValidator.java

@@ -0,0 +1,31 @@
+package model;
+
+import java.util.*;
+import java.util.stream.*;
+
+public class LadderValidator {
+    private static final Random RANDOM = new Random();
+
+    public static void validate(List<Line> lines, int width) {
+        IntStream.rangeClosed(0, width)
+                .forEach(i -> validateColumn(lines, i, width));
+    }
+
+    private static void validateColumn(List<Line> lines, int col, int width) {
+        boolean emptyColumn = lines.stream().noneMatch(line -> hasBridgeAt(line, col, width));
+        if (emptyColumn) {
+            connect(lines.get(RANDOM.nextInt(lines.size())), col, width);
+        }
+    }
+
+    private static boolean hasBridgeAt(Line line, int col, int width) {
+        if (col == 0) return line.hasBridgeAt(col);
+        if (col == width) return line.hasBridgeAt(col - 1);
+        return line.hasBridgeAt(col - 1) || line.hasBridgeAt(col);
+    }
+
+    private static void connect(Line line, int col, int width) {
+        if (col == width) line.setBridgeAt(col - 1);
+        else line.setBridgeAt(col);
+    }
+}

src/main/java/model/Line.java

@@ -0,0 +1,23 @@
+package model;
+
+import java.util.*;
+
+public class Line {
+    private final List<Boolean> points;
+
+    public Line(List<Boolean> points) {
+        this.points = points;
+    }
+
+    public List<Boolean> getPoints() {
+        return points;
+    }
+
+    public boolean hasBridgeAt(int index) {
+        return points.get(index);
+    }
+
+    public void setBridgeAt(int index) {
+        points.set(index, true);
+    }
+}

src/main/java/model/LineGenerator.java

@@ -0,0 +1,26 @@
+package model;
+
+import java.util.*;
+
+public class LineGenerator {
+    public static Lines generate(int width, int height) {
+        List<Set<Integer>> reserved = ReservedPositionGenerator.generate(width - 1, height);
+        List<Line> lines = new ArrayList<>();
+
+        for (int row = 0; row < height; row++) {
+            Line previous = getPreviousLine(lines, row);
+            Line line = SingleLineGenerator.generate(width - 1, reserved.get(row), previous);
+            lines.add(line);
+        }
+
+        LadderValidator.validate(lines, width - 1);
+        return new Lines(lines);
+    }
+
+    private static Line getPreviousLine(List<Line> lines, int row) {
+        if (row == 0) {
+            return null;
+        }
+        return lines.get(row - 1);
+    }
+}

src/main/java/model/Lines.java

@@ -0,0 +1,15 @@
+package model;
+
+import java.util.List;
+
+public class Lines {
+    private final List<Line> lines;
+
+    public Lines(List<Line> lines) {
+        this.lines = lines;
+    }
+
+    public List<Line> getLines() {
+        return lines;
+    }
+}

src/main/java/model/ReservedPositionGenerator.java

@@ -0,0 +1,19 @@
+package model;
+
+import java.util.*;
+import java.util.stream.*;
+
+public class ReservedPositionGenerator {
+    private static final Random RANDOM = new Random();
+
+    public static List<Set<Integer>> generate(int width, int height) {
+        List<Set<Integer>> reserved = IntStream.range(0, height)
+                .mapToObj(i -> new HashSet<Integer>())
+                .collect(Collectors.toList());
+
+        IntStream.range(0, width)
+                .forEach(i -> reserved.get(RANDOM.nextInt(height)).add(i));
+
+        return reserved;
+    }
+}

src/main/java/model/SingleLineGenerator.java

@@ -0,0 +1,47 @@
+package model;
+
+import java.util.*;
+import java.util.stream.*;
+
+public class SingleLineGenerator {
+    private static final Random RANDOM = new Random();
+
+    public static Line generate(int width, Set<Integer> reserved, Line prev) {
+        List<Boolean> points = new ArrayList<>(Collections.nCopies(width, false));
+
+        reserved.forEach(i -> {
+            if (isNotOverlap(points, prev, i)) {
+                points.set(i, true);
+            }
+        });
+
+        IntStream.range(0, width).forEach(i -> {
+            if (!points.get(i) && isNotOverlap(points, prev, i)) {
+                points.set(i, RANDOM.nextBoolean());
+            }
+        });
+
+        ensureOneBridge(points, prev);
+        return new Line(points);
+    }
+
+    private static boolean isNotOverlap(List<Boolean> points, Line prev, int i) {
+        if (prev != null && prev.hasBridgeAt(i)) return false;
+        if (i > 0 && points.get(i - 1)) return false;
+        return true;
+    }
+
+    private static void ensureOneBridge(List<Boolean> points, Line prev) {
+        if (points.contains(true)) return;
+
+        IntStream.range(0, points.size())
+                .filter(i -> canSetBridge(points, prev, i))
+                .findFirst()
+                .ifPresent(i -> points.set(i, true));
+    }
+
+    private static boolean canSetBridge(List<Boolean> points, Line prev, int index) {
+        return (prev == null || !prev.hasBridgeAt(index))
+                && (index == 0 || !points.get(index - 1));
+    }
+}

src/main/java/utils/ExceptionHandler.java

@@ -0,0 +1,12 @@
+package utils;
+
+import org.slf4j.*;
+
+public class ExceptionHandler {
+    private static final Logger logger = LoggerFactory.getLogger(ExceptionHandler.class);
+
+    public static void handleException(Exception e) {
+        System.err.println("시스템 오류 : " + e.getMessage());
+        logger.error("시스템 오류 : ", e);
+    }
+}

src/main/java/view/LadderView.java

@@ -0,0 +1,31 @@
+package view;
+
+import model.*;
+
+public class LadderView {
+    private static final String BRIDGE = "-----|";
+    private static final String SPACE = "     |";
+    private static final String BAR = "|";
+
+    public static void printLadder(Ladder ladder) {
+        printLines(ladder.getLines());
+    }
+
+    private static void printLines(Lines lines) {
+        lines.getLines().forEach(LadderView::printLine);
+    }
+
+    private static void printLine(Line line) {
+        System.out.print(BAR);
+        line.getPoints().forEach(LadderView::printPoint);
+        System.out.println();
+    }
+
+    private static void printPoint(Boolean point) {
+        if (point) {
+            System.out.print(BRIDGE);
+            return;
+        }
+        System.out.print(SPACE);
+    }
+}