From 33613a85afc4b1481367fbe92a17ee59c240250b Mon Sep 17 00:00:00 2001
From: Sven Eisenhauer <sven@sven-eisenhauer.net>
Date: Fri, 10 Nov 2023 15:11:48 +0100
Subject: add new repo

---
 Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp | 73 +++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp

(limited to 'Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp')

diff --git a/Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp b/Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp
new file mode 100644
index 0000000..0691d20
--- /dev/null
+++ b/Bachelor/Prog1/Prakt2/prg1p2_5/prg1p2_5.cpp
@@ -0,0 +1,73 @@
+// Programmieren 1, Praktikum 2, Aufgabe 5
+// Sven Eisenhauer
+// 06.11.2004
+//
+// file: prg1p2_5.cpp
+//
+// purpose: program to reads 2 integers from keyboard and finds all prime number twins
+//          between them, like 3 and 5 or 17 and 19
+//
+
+#include <iostream>
+using std::cin;
+using std::cout;
+using std::endl;
+
+int main()
+{
+	int iNumberA, iNumberB;
+	int iMin, iMax;
+	int iIsPrime1=0;
+	int iIsPrime2=0;
+	int iPrime1=0;
+	int iPrime2=0;
+	int iToTest=0;
+
+	cout << "Please enter 1st number: ";
+	cin >> iNumberA;
+	cout << "Please enter 2nd number: ";
+	cin >> iNumberB;
+	cout << endl;
+
+	// first find out, which is the bigger value.
+	iMax=iNumberA;
+	iMin=iNumberB;
+
+	if (iNumberB > iNumberA)
+	{
+	    iMax=iNumberB;
+	    iMin=iNumberA;
+	}
+    // First loop: Get all numbers between the 2 entered
+	for (int iOuterCounter=iMax-1;iOuterCounter>iMin;iOuterCounter--)
+	{
+		iIsPrime1=0;
+		for (int iInnerCounter=iOuterCounter-1;iInnerCounter>1;iInnerCounter--)
+		{
+			if ( 0 == iOuterCounter%iInnerCounter)
+			    iIsPrime1=1;  // actual number is NOT a prime
+		}// end inner for routine
+		if (0 == iIsPrime1)
+		{
+			iPrime1=iOuterCounter;
+			// now test, if iPrime1 - 2 is a prime
+			iIsPrime2 = 0;
+			iToTest = iOuterCounter - 2;
+			for (int iInnerCounter2=iToTest-1;iInnerCounter2>1;iInnerCounter2--)
+			{
+				if (0 == iToTest%iInnerCounter2)
+				    iIsPrime2=1;
+			}
+			if (0 == iIsPrime2)
+			    iPrime2=iToTest;
+
+			if ((0 == iIsPrime1) && (0 == iIsPrime2) && (iPrime2 > iMin))
+			    cout << iPrime1 << "\t" << iPrime2 << endl;
+		}
+		// if (iIsPrime1 && iIsPrime2)
+		//        cout << iPrime1 << "\t" << iPrime2 << endl;
+	}
+//	system ("pause");
+
+	return 0;
+}// end main
-- 
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