uebung02 aufgabe 2

uebung02/chess/ChessApp.java

@@ -5,6 +5,8 @@ public class ChessApp {
         final Piece p2 = new Piece(Kind.QUEEN, Color.WHITE, board, 4, 8);
         final Piece p3 = new Piece(Kind.KNIGHT, Color.WHITE, board, 3, 3);
         final Piece p4 = new Piece(Kind.KNIGHT, Color.BLACK, board, 4, 6);
+        final Piece p5 = new Piece(Kind.ROOK, Color.BLACK, board, 7, 6);
+        final Piece p6 = new Piece(Kind.ROOK, Color.WHITE, board, 7, 2);
         board.printBoard(System.out);
         board.check(System.out);
     }

uebung02/chess/ChessTest.java

@@ -159,4 +159,10 @@ public class ChessTest {
                     numPieces++;
         assertEquals(expectedNumPieces, numPieces);
     }
+
+    @Test
+    public void testRunWithErrors() {
+    final Piece rook = new Piece(Kind.ROOK, Color.WHITE, board, 1, 1);
+    assertEquals(Kind.ROOK, board.pieceAt(1, 1).kind);
+    }
 }

uebung02/chess/Kind.java

@@ -1,3 +1,3 @@
 public enum Kind {
-    QUEEN, KNIGHT
+    QUEEN, KNIGHT, ROOK
 }

uebung02/chess/Piece.java

@@ -25,6 +25,8 @@ class Piece {
                 return queenCharRep();
             case KNIGHT:
                 return knightCharRep();
+            case ROOK: 
+                return rookCharRep();
         }
         throw new IllegalArgumentException("Unknown piece " + kind);
     }
@@ -35,6 +37,8 @@ class Piece {
                 return queenShowPiece();
             case KNIGHT:
                 return knightShowPiece();
+            case ROOK:
+                return rookShowPiece();
         }
         throw new IllegalArgumentException("Unknown piece " + kind);
     }
@@ -45,6 +49,8 @@ class Piece {
                 return queenCanCapture(other);
             case KNIGHT:
                 return knightCanCapture(other);
+            case ROOK:
+                return rookCanCapture(other);
         }
         throw new IllegalArgumentException("Unknown piece " + kind);
     }
@@ -63,6 +69,14 @@ class Piece {
             return 'N';
     }
 
+    char rookCharRep() {
+        if (color == Color.WHITE) {
+            return 'r';
+        } else {
+            return 'R';
+        }
+    }
+
     String queenShowPiece() {
         return "" + color.toString().toLowerCase() + " queen at (" + row + ", " + col + ")";
     }
@@ -71,6 +85,10 @@ class Piece {
         return "" + color.toString().toLowerCase() + " knight at (" + row + ", " + col + ")";
     }
 
+    String rookShowPiece() {
+        return "" + color.toString().toLowerCase() + " rook at (" + row + ", " + col + ")";
+    }
+
     boolean queenCanCapture(Piece other) {
         if (board != other.board || color == other.color)
             return false;
@@ -97,4 +115,22 @@ class Piece {
         final int dc = abs(col - other.col);
         return dr == 2 && dc == 1 || dr == 1 && dc == 2;
     }
+
+    boolean rookCanCapture(Piece other) {
+        if (board != other.board || color == other.color)
+            return false;
+        if (other.row != row && other.col != col )
+            return false;
+        final int dr = signum(other.row - row);
+        final int dc = signum(other.col - col);
+        int r = row + dr;
+        int c = col + dc;
+        while (r != other.row || c != other.col) {
+            if (board.pieceAt(r, c) != null) return false;
+            r += dr;
+            c += dc;
+        }
+        return true;
+    }
+
 }

uebung02/rationals/Rational.java

@@ -0,0 +1,122 @@
+package uebung02.rationals;
+
+public class Rational {
+    private final int num, denom;
+
+
+    Rational(int num, int denom) {
+        if (denom == 0) {
+            throw new IllegalArgumentException("Zahl darf nicht 0 sein!");
+        } else {
+            int gcd = gcDivider(num, denom);
+
+            if (denom < 0) {
+                this.num = -num / gcd;
+                this.denom = -denom / gcd;
+            } else {
+                this.num = num / gcd;
+                this.denom = denom / gcd;
+            }
+        }
+    }
+
+    Rational (int num) {
+        this(num, 1);
+    }
+
+    private int gcDivider(int x, int y) {
+        //return x == 0 ? y : gcDivider(y % x, x);
+        if (x == 0) {
+            return y;
+        } else {
+            return gcDivider(y % x, x);
+        }
+    }
+
+    public int getNum() {
+        return num;
+    }
+
+    public int getDenom() {
+        return denom;
+    }
+
+    public Rational add(Rational other) {
+        return new Rational(num * other.getDenom() + denom * other.getNum(),
+        denom * other.getDenom());
+    }
+
+    public Rational add(int i) {
+        return add(new Rational(i));
+    }
+
+    public Rational sub(Rational r) {
+        return new Rational(num * r.denom - denom * r.num, denom * r.denom);
+    }
+
+    public Rational sub(int i) {
+        return this.sub(new Rational(i));
+    }
+
+    public Rational mult(Rational r) {
+        return new Rational(num * r.num, denom * r.denom);
+    }
+
+    public Rational mult(int i) {
+        return mult(new Rational(i));
+    }
+
+    public Rational div(Rational r) {
+        return new Rational(num * r.denom, denom * r.num);
+    }
+
+    public Rational div(int i) {
+        return div(new Rational(i));
+    }
+
+    @Override
+    public String toString() {
+        if (denom == 1) {
+            return "" + num;
+        } else {
+            return num + "/" + denom;
+        }
+    }
+
+    public boolean lessThan(Rational r) {
+        return this.sub(r).num < 0;
+    }
+
+    public boolean lessThan(int i) {
+        return this.sub(i).num < 0;
+    }
+
+    public boolean greaterThan(Rational r) {
+        return this.sub(r).num > 0;
+    }
+
+    public boolean greaterThan(int i) {
+        return this.sub(i).num > 0;
+    }
+
+    public boolean lessThanOrEqual(Rational r) {
+        return this.sub(r).num <= 0;
+    }
+
+    public boolean lessThanOrEqual(int i) {
+        return this.sub(i).num <= 0;
+    }
+
+    public boolean greaterThanOrEqual(Rational r) {
+        return this.sub(r).num >= 0;
+    }
+
+    public boolean isEqual(Rational r) {
+        return this.num == r.num && this.denom == r.denom;
+    }
+
+    public boolean isEqual(int i) {
+        return this.isEqual(new Rational(i));
+    }
+
+}   

uebung02/rationals/RationalDemo.java

@@ -0,0 +1,23 @@
+package uebung02.rationals;
+
+public class RationalDemo {
+    public static void main(String[] args) {
+        Rational r1 = new Rational(1, 2);
+        Rational r2 = new Rational(2, 4);
+        Rational r3 = new Rational(6, 18);
+        Rational r4 = new Rational(3, 12);
+        Rational r5 = new Rational(1);
+        Rational r6 = new Rational(2);
+        Rational r7 = new Rational(4, 3);
+
+        System.out.println("1/2 = " + r1);
+        System.out.println("2/4 = " + r2);
+        System.out.println("6/18 = " + r3);
+        System.out.println("1/2 + 2/4 = " + r1.add(r2));
+        System.out.println("1/2 - 6/18 = " + r1.sub(r3));
+        System.out.println("6/18 * 2/4 = " + r3.mult(r2));
+        System.out.println("1/2 == 2/4 ? " + r1.isEqual(r2));
+        System.out.println("2/4 == 3/12 ? " + r2.isEqual(r4));
+        System.out.println("1 + 2 / (4/3) = " + r5.add(r6.div(r7)));
+    }
+}