Triangle solution 21.11.20

src/Triangles/Dot.java

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+package Triangles;
+
+public class Dot {
+    private final double x;
+    private final double y;
+
+    public Dot(double x, double y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public double getX() {
+        return x;
+    }
+
+    public double getY() {
+        return y;
+    }
+
+
+}

src/Triangles/FileParsing.java

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+package Triangles;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+public class FileParsing {
+
+    public static List<Triangle> fileToTriangleList(File file) throws IOException {
+        List<String> stringList = Files.readAllLines(Path.of(file.getPath()));
+        return stringList.stream().map(Triangle::value).filter(Objects::nonNull).collect(Collectors.toList());
+
+    }
+
+    public static void writeInFile(List<Triangle> triangleList, File file) throws IOException {
+        if (triangleList.isEmpty()) return;
+        List<Triangle> IsoscelesTriangles = triangleList.stream().filter(Triangle::isIsosceles).collect(Collectors.toList());
+        Triangle biggestTriangle = IsoscelesTriangles.stream().min(Comparator.comparing(Solution::getTriangleScale)).get();
+
+        String triangle = biggestTriangle.toString() + "Scale: " + Solution.getTriangleScale(biggestTriangle);
+        PrintWriter out = new PrintWriter(file.getPath());
+        out.println(triangle);
+        out.close();
+    }
+}

src/Triangles/Main.java

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+package Triangles;
+
+public class Main {
+}

src/Triangles/Solution.java

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+package Triangles;
+
+import java.util.List;
+
+public class Solution {
+
+    public static double getLineLength(Dot A, Dot B) {
+        return Math.sqrt(Math.pow(A.getX() - B.getX(), 2) + Math.pow(A.getY() - B.getY(), 2));
+    }
+
+    public static double getTriangleScale(Triangle triangle) {
+        double sideA = Solution.getLineLength(triangle.getA(), triangle.getB());
+        double sideB = Solution.getLineLength(triangle.getB(), triangle.getC());
+        double sideC = Solution.getLineLength(triangle.getA(), triangle.getC());
+
+        double p = (sideA + sideB + sideC) / 2;
+
+        return Math.sqrt(p*(p - sideA)*(p - sideB)*(p - sideC));
+    }
+
+
+}

src/Triangles/Triangle.java

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+package Triangles;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Triangle {
+    private final Dot A;
+    private final Dot B;
+    private final Dot C;
+
+    public Triangle(Dot a, Dot b, Dot c) {
+        A = a;
+        B = b;
+        C = c;
+    }
+
+    public Dot getA() {
+        return A;
+    }
+
+    public Dot getB() {
+        return B;
+    }
+
+    public Dot getC() {
+        return C;
+    }
+
+    public boolean isTriangle() {
+        return (C.getX() - A.getX()) / (B.getX() - A.getX()) != (C.getY() - A.getY()) / (B.getY() - A.getY());
+    }
+
+
+    public boolean isIsosceles() {
+        if (isTriangle()) {
+            double sideA = Solution.getLineLength(A, B);
+            double sideB = Solution.getLineLength(B, C);
+            double sideC = Solution.getLineLength(A, C);
+            return (sideA == sideB) || (sideA == sideC) || (sideB == sideC);
+        }
+        return false;
+    }
+
+    public static Triangle value(String s) {
+        String[] coords = s.split(" ");
+        if (coords.length < 6) {
+            return null; // Not enough data
+        }
+        List<Dot> dots = new ArrayList<>();
+        for (int i = 0; i < 6; i += 2) {
+            dots.add(new Dot(Double.parseDouble(coords[i]), Double.parseDouble(coords[i + 1])));
+        }
+        Triangle triangle = new Triangle(dots.get(0), dots.get(1), dots.get(2));
+        return triangle.isTriangle() ? triangle : null;
+    }
+
+    @Override
+    public String toString() {
+        return "Triangle:" +
+                "Ax=" + A.getX() + "Ay=" + A.getY() +
+                ", Bx=" + B.getX() + "By=" + B.getY() +
+                ", Cx=" + C.getX() + "Cy=" + C.getY();
+    }
+}