From 643f4515548365c5eb1f8f0c27173060dde2fde4 Mon Sep 17 00:00:00 2001
From: Alicia Dietrich <dietrichalicia.ad@gmail.com>
Date: Mon, 4 Dec 2023 21:55:59 +0200
Subject: [PATCH] feat: add Uebung 1 und 2

---
 Uebung5/Aufgabe1/Fibonacci.java     | 30 ++++++++++++++++++
 Uebung5/Aufgabe2/QueensProblem.java | 49 +++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)
 create mode 100644 Uebung5/Aufgabe1/Fibonacci.java
 create mode 100644 Uebung5/Aufgabe2/QueensProblem.java

diff --git a/Uebung5/Aufgabe1/Fibonacci.java b/Uebung5/Aufgabe1/Fibonacci.java
new file mode 100644
index 0000000..0556647
--- /dev/null
+++ b/Uebung5/Aufgabe1/Fibonacci.java
@@ -0,0 +1,30 @@
+public class Fibonacci {
+
+    public static void main(String[] args) {
+        int iterativ = printFibonacciIterative(45);
+        System.out.println(iterativ);
+        int recursive = fibonacciRecursive(45);
+        System.out.println(recursive);
+    }
+
+    public static int printFibonacciIterative(int n) {
+        //Hilfsvariablen a und b
+        int a = 1, b = 1;
+        int sum = 0;
+        //for-Schleife für die iterative Berechnung der Fibonacci Folge
+        for (int i = 1; i < n-1; i++) {
+            sum = a + b;
+            a = b;
+            b = sum;
+        }
+        return sum;
+    }
+
+    private static int fibonacciRecursive(int a) {
+        if (a == 1 || a == 2) {
+            return 1;
+        } else {
+            return fibonacciRecursive(a - 1) + fibonacciRecursive(a - 2);
+        }
+    }
+}
diff --git a/Uebung5/Aufgabe2/QueensProblem.java b/Uebung5/Aufgabe2/QueensProblem.java
new file mode 100644
index 0000000..8966509
--- /dev/null
+++ b/Uebung5/Aufgabe2/QueensProblem.java
@@ -0,0 +1,49 @@
+public class QueensProblem {
+
+    public static void main(String[] args) {
+        //Initialisiere Schachfeld 8x8
+        boolean[][] queen = new boolean[8][8];
+        int counter = solutions(queen, 0);
+        System.out.println(counter);
+    }
+
+    private static int solutions(boolean[][] queen, int row) {
+        if (row == queen.length) {
+            return 1;
+        }
+
+        int counter = 0;
+        for (int col = 0; col < queen.length; col++) {
+            if (!isPositionSave(queen, row, col)) {
+                continue;
+            }
+
+            queen[row][col] = true;
+            counter += solutions(queen, row + 1);
+            queen[row][col] = false;
+        }
+
+        return counter;
+    }
+
+    public static boolean isPositionSave(boolean[][] queen, int row, int col) {
+
+        for (int i = 0; i < row; i++) {
+            int dC = row - i;
+            // Teste Spalte
+            if (queen[i][col]) {
+                return false;
+            }
+            // Teste linke Diagonale
+            if (col - dC >= 0 && queen[i][col - dC]) {
+                return false;
+            }
+            // Teste rechte Diagonale
+            if (col + dC < queen.length && queen[i][col + dC]) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}