Optimization

.gitignore

@@ -29,3 +29,4 @@ bin/
 .DS_Store
 /Medien/Bilder & Co/Goldfrosch.pptx
 /Medien/Bilder & Co/Goldfrosch.xlsx
+/src/HZ/

.idea/misc.xml

@@ -1,5 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="21" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_X" default="true" project-jdk-name="openjdk-22" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

README.md

@@ -8,7 +8,7 @@ Dateien wie Bilder die zur Lösung einer Aufgabe gehören sind in <br><ins>Medie
 ## Bisher vollständig vorhanden:
 - Vorlesung 3 komplett
 - Vorlesung 4 komplett
-- Vorlesung 5 Aufgabe 1 & 3 von 3
+- Vorlesung 5 komplett
 - Vorlesung 6 komplett
 - Vorlesung 7 komplett
 - Vorlesung 8 komplett
@@ -16,8 +16,6 @@ Dateien wie Bilder die zur Lösung einer Aufgabe gehören sind in <br><ins>Medie
 - Vorlesung 10 komplett
 
 ## Angefangene unfertige Lösungen:
-- Damenproblem: VL 5 Aufgabe 2
-<br>Nicht die gewünschte rekursive Backtracking-Implementierung
 - JavaDoc: VL 9 Aufgabe 1
 <br>Das Tool mag mich nicht
 

src/part4/aufg3.java

@@ -9,7 +9,7 @@ public class aufg3 {
     // =====================
 
     public static void main(String[] args){
-        int MAXIMUM = 10_000_000;  // takes about 13 seconds(!!)
+        int MAXIMUM = 100_000_000;  // takes about 4 seconds(!!)
         int MAX_PER_ROW = 20;
 
         boolean[] primes = new boolean[MAXIMUM];
@@ -17,7 +17,7 @@ public class aufg3 {
         Arrays.fill(primes, true);
 
         for(int i=2; i < MAXIMUM * 0.5; i++){
-            for(int j=2; j < ((MAXIMUM*1.0)/i); j++){
+            for(int j=i; j < ((MAXIMUM*1.0)/i); j++){
 
                 int index = i * j;
 

src/part5/aufg1.java

@@ -21,12 +21,12 @@ public class aufg1 {
             result = 0;
         } else if (number < 2) {
             result =  1;
-        }else if (number == 10) {   // Optimization1
-            result =  89;
-        }else if (number == 20) {   // Optimization2
-            result =  10946;
-        }else if (number == 30) {   // Optimization3
-            result =  1346269;
+//        }else if (number == 10) {   // Optimization1
+//            result =  89;
+//        }else if (number == 20) {   // Optimization2
+//            result =  10946;
+//        }else if (number == 30) {   // Optimization3
+//            result =  1346269;
         }else {
             result =  fibonacciRec(number-1) + fibonacciRec(number-2);
         }
@@ -34,11 +34,27 @@ public class aufg1 {
         return result;
     }
 
+    public static int fiboTailRec(int number){
+        return helper(++number, new int[] {0,1});
+    }
+
+    private static int helper(int number, int[] result){
+        if (number < 0){
+            return 0;
+        }
+        if (number < 2){
+            return result[number];
+        }
+
+        return helper(number-1, new int[] {result[1], result[0] + result[1]});
+    }
+
     public static void main(String[] agrs){
         // Fib(47) causes an Integer Overflow
         for (int i=0; i<46; i++) {
             System.out.println("i " + i + ": " + fibonacciIter(i));
             System.out.println("i " + i + ": " + fibonacciRec(i));
+            System.out.println("i " + i + ": " + fiboTailRec(i));
             System.out.println("==========");
         }
     }

src/part5/aufg2/Demo.java

@@ -3,21 +3,11 @@ package part5.aufg2;
 public class Demo {
     public static void main(String[] args) {
         Queenproblem Q = new Queenproblem();
-        Q.setField(new int[]{2,4,6,8,1,3,5,0});
-        Q.print();
-        System.out.println("============= ALL");
-        System.out.println(Q.isPossible(7,8));
-        System.out.println("============= Horiz");
-        System.out.println(Q.checkHorizontal(7));
-        System.out.println("============= Vert");
-        System.out.println(Q.checkVertical(8));
-        System.out.println("============= Rising");
-        System.out.println(Q.checkRisingDiagonal(7,8));
-        System.out.println("============= Falling");
-        System.out.println(Q.checkFallingDiagonal(7,8));
-
-
-    }
+        Q.solve();
+        System.out.println("====================================\n");
+        Q.setField(new int[]{0,0,0,0,0,0,0,0});
+        Q.solve();
     }
+}
 
 

src/part5/aufg2/Queenproblem.java

@@ -6,15 +6,20 @@ public class Queenproblem {
     // 0 means empty
     // 1-8 is the y position of the Queen
     int[] field;
-    int[][] field2D;
+
     public Queenproblem(){
         this.field = new int[8];
+        makeBoardEmpty();
     }
 
     public void setField(int[] field) {
         this.field = field;
     }
 
+    public void makeBoardEmpty(){
+        this.setField(new int[] {0,0,0,0,0,0,0,0});
+    }
+
     private int[][] make2D(){
         int[][] field = new int[8][8];
 
@@ -26,10 +31,7 @@ public class Queenproblem {
             try {
                 int yPosition = this.field[i];
                 field[yPosition-1][i] = 1;   // -1 to handle 0 as empty and 8 as lowest possible with actual index 7
-            }catch (IndexOutOfBoundsException e){
-                ;
-                //System.out.println("Ignored Index Error while making it 2D");
-            }
+            }catch (IndexOutOfBoundsException e){/* System.out.println("Ignored Index Error while making it 2D") */}
         }
 
         return field;
@@ -44,10 +46,7 @@ public class Queenproblem {
     }
 
     public boolean checkVertical(int col){
-        if (this.field[col-1] != 0){
-            return false;
-        }
-        return true;
+        return this.field[col - 1] == 0;
     }
 
     public boolean checkHorizontal(int row){
@@ -77,9 +76,7 @@ public class Queenproblem {
                         return false;
                     }
                 }
-            }catch (IndexOutOfBoundsException e){
-                ; // Skip Iteration with IndexError
-            }
+            }catch (IndexOutOfBoundsException e){/* Skip Iteration with IndexError */}
 
             // cannot be in the same try block.
             // Exceptions in the + direction stop execution of - prematurely
@@ -89,9 +86,7 @@ public class Queenproblem {
                         return false;
                     }
                 }
-            }catch (IndexOutOfBoundsException e){
-                ; // Skip Iteration with IndexError
-            }
+            }catch (IndexOutOfBoundsException e){/* Skip Iteration with IndexError*/ }
         }
         return true;
     }
@@ -102,63 +97,44 @@ public class Queenproblem {
         for (int i = 0; i < 8; i++) {
             try {
                 if (this.field[col-1+i] != 0) {
-                    if (this.field[col - 1 + i] == row - i) {
+                    if (this.field[col-1+i] == row-i) {
                         return false;
                     }
                 }
-            }catch (IndexOutOfBoundsException e){
-                ;
-            }
+            }catch (IndexOutOfBoundsException e){}
             try {
-                if (this.field[col-1-1] != 0) {
-                    if (this.field[col - 1 - i] == row + 1) {
+                if (this.field[col-1-i] != 0) {
+                    if (this.field[col-1-i] == row+i) {
                         return false;
                     }
                 }
-            }catch (IndexOutOfBoundsException e){
-                ;
-            }
+            }catch (IndexOutOfBoundsException e){}
         }
         return true;
     }
     public boolean isPossible(int row, int col){
-
-        if(checkHorizontal(row) == false){
+        if(!checkHorizontal(row)){
             return false;
         }
-
-        if (checkVertical(col) == false) {
+        if (!checkVertical(col)) {
             return false;
         }
-
-        // Diagonal \
-        if (checkFallingDiagonal(row, col) == false){
+        if (!checkFallingDiagonal(row, col)){
             return false;
         }
-
-
-        if (checkRisingDiagonal(row, col) == false){
+        if (!checkRisingDiagonal(row, col)){
             return false;
         }
         return true;
     }
 
-    public void solve(int queensPlaced){
-        field2D = make2D();
-        if (queensPlaced == 6){
-            System.out.println("solved 6");
-        }
+    public void solve(){
         for (int col = 1; col < 9; col++) {
-            if(col == 8) {
-                System.out.println("solving the last one");
-            }
             if (this.field[col-1] == 0) {
                 for (int row = 1; row < 9; row++) {
                     if (isPossible(row,col)) {
                         this.field[col-1] = row;
-                        queensPlaced++;
-                        this.solve(queensPlaced);
-                        queensPlaced--;
+                        this.solve();
                         this.field[col-1] = 0;
                     }
                 }