From 0b5c76b5757bca63a20b72fa959f74747b465d2b Mon Sep 17 00:00:00 2001
From: Angeld55 <angel_dimitriev@abv.bg>
Date: Fri, 23 Oct 2020 14:34:45 +0300
Subject: added examples for sem 3

---
 README.md                               |  3 ++-
 Sem. 3/Contains5.cpp                    | 32 ++++++++++++++++++++++++++++++
 Sem. 3/DevidersCount_PrimalityCheck.cpp | 29 +++++++++++++++++++++++++++
 Sem. 3/GCD_solution1.cpp                | 32 ++++++++++++++++++++++++++++++
 Sem. 3/GCD_solution2.cpp                | 35 +++++++++++++++++++++++++++++++++
 Sem. 3/GCD_solution3_Eucid.cpp          | 25 +++++++++++++++++++++++
 Sem. 3/PrintEvenNumbers.cpp             | 27 +++++++++++++++++++++++++
 Sem. 3/SumOfDigits.cpp                  | 22 +++++++++++++++++++++
 8 files changed, 204 insertions(+), 1 deletion(-)
 create mode 100644 Sem. 3/Contains5.cpp
 create mode 100644 Sem. 3/DevidersCount_PrimalityCheck.cpp
 create mode 100644 Sem. 3/GCD_solution1.cpp
 create mode 100644 Sem. 3/GCD_solution2.cpp
 create mode 100644 Sem. 3/GCD_solution3_Eucid.cpp
 create mode 100644 Sem. 3/PrintEvenNumbers.cpp
 create mode 100644 Sem. 3/SumOfDigits.cpp

diff --git a/README.md b/README.md
index 77eb559..9bc86fa 100644
--- a/README.md
+++ b/README.md
@@ -2,4 +2,5 @@
 
 
  - **Тема 1 (09.10.2020) :**  Променливи. Типове променливи. Оператори. Преобразуване между типове.
-.- **Тема 1 (16.10.2020) :**  Приоритет на операторите. Асоциативност. Условни провеки (if, switch)
+ - **Тема 2 (16.10.2020) :**  Приоритет на операторите. Асоциативност. Условни провеки (if, switch)
+ - **Тема 3 (23.10.2020) :**  Жизнен цикъл на променливите. Оператори за цикъл(while, for). Оператор break. Задачи
\ No newline at end of file
diff --git a/Sem. 3/Contains5.cpp b/Sem. 3/Contains5.cpp
new file mode 100644
index 0000000..78d13f0
--- /dev/null
+++ b/Sem. 3/Contains5.cpp	
@@ -0,0 +1,32 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	bool foundFive = false;
+	while (n != 0)
+	{
+		int lastDigit = n % 10;
+		if (lastDigit == 5)
+		{
+			foundFive = true;
+			break;
+		}
+		n /= 10;
+	}
+	
+	if (foundFive)
+	{
+		cout << "yes";
+	}
+	else
+	{
+		cout << "no";
+	}
+	
+
+}
\ No newline at end of file
diff --git a/Sem. 3/DevidersCount_PrimalityCheck.cpp b/Sem. 3/DevidersCount_PrimalityCheck.cpp
new file mode 100644
index 0000000..7584722
--- /dev/null
+++ b/Sem. 3/DevidersCount_PrimalityCheck.cpp	
@@ -0,0 +1,29 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	unsigned int n; //allways positive int
+	cin >> n;
+
+	int divCount = 0;
+
+	for (int i = 1; i <= n; i++)
+	{
+		if (n%i == 0)
+			divCount++;
+	}
+	cout << divCount;
+	if (divCount == 2)
+	{
+		cout << "Prime";
+	}
+	else
+	{
+		cout << "Not a prime";
+	}
+
+	
+
+}
\ No newline at end of file
diff --git a/Sem. 3/GCD_solution1.cpp b/Sem. 3/GCD_solution1.cpp
new file mode 100644
index 0000000..58ea35b
--- /dev/null
+++ b/Sem. 3/GCD_solution1.cpp	
@@ -0,0 +1,32 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n, k;
+
+	cin >> n >> k;
+
+	if (n < k) //swap
+	{
+		int temp = n;
+		n = k;
+		k = temp;
+	}
+
+	int devider = 1;
+	int result; 
+	while (devider <= k)
+	{
+		if (n % devider == 0 && k % devider == 0)
+		{
+			result = devider;
+		}
+		devider++;
+	}
+
+	cout << result;
+	
+
+}
\ No newline at end of file
diff --git a/Sem. 3/GCD_solution2.cpp b/Sem. 3/GCD_solution2.cpp
new file mode 100644
index 0000000..ba06c89
--- /dev/null
+++ b/Sem. 3/GCD_solution2.cpp	
@@ -0,0 +1,35 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n, k;
+
+	cin >> n >> k;
+
+	if (n < k) //swap
+	{
+		int temp = n;
+		n = k;
+		k = temp;
+		
+	}
+	int devider = k;
+	bool foundSolution = false;
+
+
+	while (!foundSolution)
+	{
+		if (n % devider == 0 && k % devider == 0)
+			foundSolution = true;
+		else
+			devider--;
+		
+		
+	}
+	cout << devider;
+
+	
+
+}
\ No newline at end of file
diff --git a/Sem. 3/GCD_solution3_Eucid.cpp b/Sem. 3/GCD_solution3_Eucid.cpp
new file mode 100644
index 0000000..f190a90
--- /dev/null
+++ b/Sem. 3/GCD_solution3_Eucid.cpp	
@@ -0,0 +1,25 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n, k;
+
+	cin >> n >> k;
+
+	if (n < k) //swap
+	{
+		int temp = n;
+		n = k;
+		k = temp;
+	}
+	
+	while (k != 0)
+	{
+		int div = n % k;
+		n = k;
+		k = div;
+	}
+	cout << n << endl;
+}
\ No newline at end of file
diff --git a/Sem. 3/PrintEvenNumbers.cpp b/Sem. 3/PrintEvenNumbers.cpp
new file mode 100644
index 0000000..e9a2231
--- /dev/null
+++ b/Sem. 3/PrintEvenNumbers.cpp	
@@ -0,0 +1,27 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+	
+	int j = 0;
+	while (j <= n)
+	{
+		cout << j << endl;
+		j += 2;
+	}
+	
+	//Here the variable j is reachable! 
+
+
+	for (int i = 0; i <=n; i++)
+	{
+		cout << i << endl;
+	}
+	// Here the variable i is NOT reachable.
+
+
+}
\ No newline at end of file
diff --git a/Sem. 3/SumOfDigits.cpp b/Sem. 3/SumOfDigits.cpp
new file mode 100644
index 0000000..6777a42
--- /dev/null
+++ b/Sem. 3/SumOfDigits.cpp	
@@ -0,0 +1,22 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	int digitSum = 0;
+
+	while (n != 0)
+	{
+		int lastDigit = n % 10; //extracts last digit
+		digitSum += lastDigit; //adds it to the sum
+		n /= 10; //removes last digit
+	}
+
+	cout << digitSum;
+	
+
+}
\ No newline at end of file
-- 
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