Solved all exercises from sem. 03

13 files changed, 273 insertions, 0 deletions

diff --git a/Sem. 03/Solutions/01. Digit_Sum.cpp b/Sem. 03/Solutions/01. Digit_Sum.cpp
new file mode 100644
index 0000000..7bedf7f
--- /dev/null
+++ b/Sem. 03/Solutions/01. Digit_Sum.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n = 1, sum = 0;
+	while (n != 0)
+	{
+		cin >> n;
+		sum += n;
+	}
+	cout << sum << endl;
+}
diff --git a/Sem. 03/Solutions/02. Sorted_Common_Divisors.cpp b/Sem. 03/Solutions/02. Sorted_Common_Divisors.cpp
new file mode 100644
index 0000000..75af7ea
--- /dev/null
+++ b/Sem. 03/Solutions/02. Sorted_Common_Divisors.cpp
@@ -0,0 +1,17 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n, k;
+	cin >> n >> k;
+
+	// i = smaller number
+	for (int i = (n < k) ? n : k; i > 0; i--)
+	{
+		if (n % i == 0 && k % i == 0)
+			cout << i << " ";
+	}
+	cout << endl;
+}
diff --git a/Sem. 03/Solutions/03. Remove_Middle_Digits.cpp b/Sem. 03/Solutions/03. Remove_Middle_Digits.cpp
new file mode 100644
index 0000000..5874ec4
--- /dev/null
+++ b/Sem. 03/Solutions/03. Remove_Middle_Digits.cpp
@@ -0,0 +1,24 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	int digits = 0, reversedN;
+	for (int i = n; i != 0; i /= 10)
+		digits++;
+
+	int tenToTheHalf = 1; // ten to the power of digits to take from each end
+	int digitsToTakeFromEachEnd = digits / 2 + (digits % 2 - 1);
+	for (int i = 0; i < digitsToTakeFromEachEnd; i++)
+		tenToTheHalf *= 10;
+
+	int tenToTheMiddle = (digits % 2 == 0) ? 100 : 10; // ten to the power of digits to remove from the middle
+
+	int resultNumber = (n % tenToTheHalf) + (n / tenToTheHalf / tenToTheMiddle) * tenToTheHalf;
+
+	cout << resultNumber << ", " << resultNumber + 1 << endl;
+}
diff --git a/Sem. 03/Solutions/04. Primes_In_Interval.cpp b/Sem. 03/Solutions/04. Primes_In_Interval.cpp
new file mode 100644
index 0000000..a1510da
--- /dev/null
+++ b/Sem. 03/Solutions/04. Primes_In_Interval.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+int main()
+{
+	int a, b;
+	cin >> a >> b;
+
+	if (a < 2) a = 2;
+
+	for (int i = a; i <= b; i++)
+	{
+		bool isPrime = true;
+		int rootOfI = sqrt(i);
+		for (int j = 2; j <= rootOfI; j++)
+		{
+			if (i % j == 0)
+			{
+				isPrime = false;
+				break;
+			}
+		}
+
+		if (isPrime)
+			cout << i << " ";
+	}
+	cout << endl;
+}
diff --git a/Sem. 03/Solutions/05. Power_Of_Two.cpp b/Sem. 03/Solutions/05. Power_Of_Two.cpp
new file mode 100644
index 0000000..9cbe442
--- /dev/null
+++ b/Sem. 03/Solutions/05. Power_Of_Two.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	while(n % 2 == 0 && n > 1)
+		n /= 2;
+
+	cout << ((n == 1) ? "true" : "false") << endl;
+}
diff --git a/Sem. 03/Solutions/06. Polynomial_Solutions.cpp b/Sem. 03/Solutions/06. Polynomial_Solutions.cpp
new file mode 100644
index 0000000..375f6ec
--- /dev/null
+++ b/Sem. 03/Solutions/06. Polynomial_Solutions.cpp
@@ -0,0 +1,17 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int a, b, c, d, e;
+	cin >> a >> b >> c >> d >> e;
+
+	double fx;
+	for (int x = -100; x <= 100; x++) {
+		fx = a * x*x*x*x + b * x*x*x + c * x*x + d * x + e;
+		if(fx >= 0)
+			cout << x << " ";
+	}
+	cout << endl;
+}
diff --git a/Sem. 03/Solutions/08. Triangle.cpp b/Sem. 03/Solutions/08. Triangle.cpp
new file mode 100644
index 0000000..72fec46
--- /dev/null
+++ b/Sem. 03/Solutions/08. Triangle.cpp
@@ -0,0 +1,16 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = 1; i <= n; i++)
+	{
+		for(int j = 0; j < i; j++)
+			cout << "$ ";
+		cout << endl;
+	}
+}
diff --git a/Sem. 03/Solutions/09. Lefthand_Triangle.cpp b/Sem. 03/Solutions/09. Lefthand_Triangle.cpp
new file mode 100644
index 0000000..4d6e9b7
--- /dev/null
+++ b/Sem. 03/Solutions/09. Lefthand_Triangle.cpp
@@ -0,0 +1,22 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = -n + 1; i < n; i++)
+	{
+		int absI = ((i > 0) ? i : -i), number = 0;
+
+		for(int j = n - absI; j > 0; j--)
+			(number *= 10) += j;
+
+		for(int j = absI; j > 0; j--)
+			cout << " ";
+
+		cout << number << endl;
+	}
+}
diff --git a/Sem. 03/Solutions/10. Spiral_Numbers.cpp b/Sem. 03/Solutions/10. Spiral_Numbers.cpp
new file mode 100644
index 0000000..0b9d2a9
--- /dev/null
+++ b/Sem. 03/Solutions/10. Spiral_Numbers.cpp
@@ -0,0 +1,24 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = 0; i < n; i++)
+	{
+		int previous = i + 1;
+		for(int j = 0; j < n; j++)
+		{
+			if (j == 0)
+				cout << previous << " ";
+			else if (j % 2 == 1)
+				cout << (previous += (n-i-1) * 2 + 1) << " ";
+			else
+				cout << (previous += i*2 + 1) << " ";
+		}
+		cout << endl;
+	}
+}
diff --git a/Sem. 03/Solutions/11.Spiral_Numbers_2.cpp b/Sem. 03/Solutions/11.Spiral_Numbers_2.cpp
new file mode 100644
index 0000000..3ff0f16
--- /dev/null
+++ b/Sem. 03/Solutions/11.Spiral_Numbers_2.cpp
@@ -0,0 +1,26 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = 0, previous = 0; i < n; i++)
+	{
+		int modifier = 1;
+		if (i % 2 == 1)
+		{
+			previous += n + 1;
+			modifier = -1;
+		}
+			
+		for(int j = 0; j < n; j++)
+			cout << (previous += modifier) << " ";
+
+		cout << endl;
+		if (i % 2 == 1)
+			previous += n - 1;
+	}
+}
diff --git a/Sem. 03/Solutions/12. Frame.cpp b/Sem. 03/Solutions/12. Frame.cpp
new file mode 100644
index 0000000..3d19376
--- /dev/null
+++ b/Sem. 03/Solutions/12. Frame.cpp
@@ -0,0 +1,17 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = 0; i < n; i++)
+	{
+		cout << ((i == 0 || i == n-1) ? "+" : "|");
+		for(int j = 0; j < n - 2; j++)
+			cout << "-";
+		cout << ((i == 0 || i == n-1) ? "+" : "|") << endl;
+	}
+}
diff --git a/Sem. 03/Solutions/13. Dumbbell.cpp b/Sem. 03/Solutions/13. Dumbbell.cpp
new file mode 100644
index 0000000..d59cfac
--- /dev/null
+++ b/Sem. 03/Solutions/13. Dumbbell.cpp
@@ -0,0 +1,26 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	int rowWidth = 5 * n / 2;
+	int evenness = 1 - n % 2;
+	for(int i = 0; i < n; i++)
+	{
+		if (i == 0 || i == n - 1)
+		{
+			for(int j = 0; j < rowWidth; j++)
+				cout << ((j == n || j == n + evenness) ? " " : ".");
+		}
+		else
+		{
+			for(int j = 0; j < rowWidth; j++)
+				cout << ((j == 1 || j == 1 + evenness || j == rowWidth - 2 || j == rowWidth - 2 - evenness) ? " " : ".");
+		}
+		cout << endl;
+	}
+}
diff --git a/Sem. 03/Solutions/14. Tree.cpp b/Sem. 03/Solutions/14. Tree.cpp
new file mode 100644
index 0000000..b47daa4
--- /dev/null
+++ b/Sem. 03/Solutions/14. Tree.cpp
@@ -0,0 +1,26 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+	int n;
+	cin >> n;
+
+	for(int i = 1; i <= n; i++)
+	{
+		for(int j = n - i; j > 0; j--)
+			cout << " ";
+		for(int j = -i + 1; j < i; j++)
+		{
+			cout << i - ((j < 0) ? -j : j);
+		}
+		cout << endl;
+	}
+	for(int i = n - 1; i > 0; i--)
+	{
+		for (int j = n - 1; j > 0; j--)
+			cout << " ";
+		cout << i << endl;
+	}
+}