From fdc84e38766d9ed6f6ce0c93d424d105d58590ff Mon Sep 17 00:00:00 2001
From: Johannes Theiner <j.theiner@live.de>
Date: Sun, 9 Dec 2018 19:40:58 +0100
Subject: [PATCH] A4: Implementierung Heap ~ iterativ fertig

---
 algodat.iml                                   |  21 ----
 .../algodat/praktikum/blatt4/Heap.java        | 115 ++++++++++++++++++
 .../algodat/praktikum/blatt4/HeapMain.java    |  34 ++++++
 .../studium/algodat/praktikum/HeapTest.java   |  18 +++
 4 files changed, 167 insertions(+), 21 deletions(-)
 delete mode 100644 algodat.iml
 create mode 100644 src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/Heap.java
 create mode 100644 src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/HeapMain.java
 create mode 100644 src/test/java/xyz/joethei/studium/algodat/praktikum/HeapTest.java

diff --git a/algodat.iml b/algodat.iml
deleted file mode 100644
index 39e64ba..0000000
--- a/algodat.iml
+++ /dev/null
@@ -1,21 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
-    <output url="file://$MODULE_DIR$/target/classes" />
-    <output-test url="file://$MODULE_DIR$/target/test-classes" />
-    <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
-      <excludeFolder url="file://$MODULE_DIR$/target" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.junit.jupiter:junit-jupiter-api:5.3.1" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.apiguardian:apiguardian-api:1.0.0" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.opentest4j:opentest4j:1.1.1" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.junit.platform:junit-platform-commons:1.3.1" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.junit.jupiter:junit-jupiter-engine:5.3.1" level="project" />
-    <orderEntry type="library" scope="TEST" name="Maven: org.junit.platform:junit-platform-engine:1.3.1" level="project" />
-    <orderEntry type="library" name="Maven: org.jetbrains:annotations:13.0" level="project" />
-  </component>
-</module>
\ No newline at end of file
diff --git a/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/Heap.java b/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/Heap.java
new file mode 100644
index 0000000..e5e1976
--- /dev/null
+++ b/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/Heap.java
@@ -0,0 +1,115 @@
+package xyz.joethei.studium.algodat.praktikum.blatt4;
+
+import java.util.Arrays;
+
+public class Heap<E extends Comparable<E>> {
+
+    private Object[] array;
+    private int last = 0;
+    private int capacity;
+    private int swapCount = 0;
+
+
+    public Heap(int capacity) {
+        array = new Object[capacity + 1];
+        this.capacity = capacity;
+    }
+
+    public Heap(Object[] array) {
+        this.capacity = array.length + 1;
+        this.array = array;
+        this.last = array.length-1;
+        down();
+    }
+
+    public int size() {
+        return last;
+    }
+
+    public boolean isEmpty() {
+        return size() == 0;
+    }
+
+    public int getSwapCount() {
+        return swapCount;
+    }
+
+    public E min() throws RuntimeException {
+        if (isEmpty())
+            throw new RuntimeException("The heap is empty.");
+        else
+            return (E) array[1];
+    }
+
+    private int compare(Object x, Object y) {
+        return ((E) x).compareTo((E) y);
+    }
+
+    public void insert(E e) throws RuntimeException {
+        if (size() == capacity)
+            throw new RuntimeException("Heap overflow.");
+        else {
+            last++;
+            array[last] = e;
+            up();
+        }
+    }
+
+    public E removeMin() throws RuntimeException {
+        if (isEmpty())
+            throw new RuntimeException("Heap is empty.");
+        else {
+            E min = min();
+            array[1] = array[last];
+            last--;
+            down();
+            return min;
+        }
+    }
+
+    private void down() {
+        int index = 1;
+        while (true) {
+            int child = index * 2;
+            if (child > size())
+                break;
+            if (child + 1 <= size()) {
+                child = findMin(child, child + 1);
+            }
+            if (compare(array[index], array[child]) <= 0)
+                break;
+            swap(index, child);
+            index = child;
+        }
+    }
+
+
+    private void up() {
+        int index = size();
+        while (index > 1) {
+            int parent = index / 2;
+            if (compare(array[index], array[parent]) >= 0)
+                break;
+            swap(index, parent);
+            index = parent;
+        }
+    }
+
+    private void swap(int i, int j) {
+        swapCount++;
+        Object temp = array[i];
+        array[i] = array[j];
+        array[j] = temp;
+    }
+
+    private int findMin(int leftChild, int rightChild) {
+        if (compare(array[leftChild], array[rightChild]) <= 0)
+            return leftChild;
+        else
+            return rightChild;
+    }
+
+    public String toString() {
+        return Arrays.toString(array);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/HeapMain.java b/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/HeapMain.java
new file mode 100644
index 0000000..806b785
--- /dev/null
+++ b/src/main/java/xyz/joethei/studium/algodat/praktikum/blatt4/HeapMain.java
@@ -0,0 +1,34 @@
+package xyz.joethei.studium.algodat.praktikum.blatt4;
+
+public class HeapMain {
+
+    public static void main(String[] args) {
+        int[] n = new int[]{1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535};
+
+        System.out.println("iterativ");
+        for(int i : n) {
+            Heap heap = getHeap(i);
+            System.out.println(i + " : " + heap.getSwapCount());
+        }
+
+        System.out.println("geblockt");
+        for(int i : n) {
+            Integer[] array = new Integer[i];
+            for (int j = i; j > 0; j--) {
+                array[j-1] = j;
+            }
+            Heap heap = new Heap(array);
+            System.out.println(i + " : " + heap.getSwapCount());
+        }
+
+    }
+
+    public static Heap getHeap(int n) {
+        Heap<Integer> heap = new Heap<>(n);
+
+        for (int i = n; i > 0; i--) {
+            heap.insert(i);
+        }
+        return heap;
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/xyz/joethei/studium/algodat/praktikum/HeapTest.java b/src/test/java/xyz/joethei/studium/algodat/praktikum/HeapTest.java
new file mode 100644
index 0000000..710da5b
--- /dev/null
+++ b/src/test/java/xyz/joethei/studium/algodat/praktikum/HeapTest.java
@@ -0,0 +1,18 @@
+package xyz.joethei.studium.algodat.praktikum;
+
+import org.junit.jupiter.api.Test;
+import xyz.joethei.studium.algodat.praktikum.blatt4.HeapMain;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class HeapTest {
+
+    @Test
+    void iterativ() {
+        int[] n = new int[]{1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535};
+        int[] res = new int[]{0, 2, 10, 34, 98, 258, 642, 1538, 3586, 8194, 18434, 40962, 90114, 196610, 425986, 917506};
+        for (int i = 0; i < 15; i++) {
+            assertEquals(HeapMain.getHeap(n[i]).getSwapCount(), res[i]);
+        }
+    }
+}
\ No newline at end of file