Lab 1

lab_1/1b-1.cpp

@@ -0,0 +1,8 @@
+#include <iostream>
+#include "1b.h"
+//
+int main()
+{
+    std::cout << "Is 5 even? "<< is_even(5) << "\n";
+    std::cout << "Is 56462 even? "<< is_even(56462) << "\n";
+}

lab_1/1b-2.cpp

@@ -0,0 +1,12 @@
+#include "1b.h"
+bool is_even(int num)
+{
+    if (num%2 == 0)
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}

lab_1/1b.h

@@ -0,0 +1 @@
+bool is_even(int num);

lab_1/2.py

@@ -0,0 +1,4 @@
+def scalar_product(x, y, dimension):
+    sum = 0.0
+    for i in range(dimension): sum += x[i]*y[i]
+    return sum

lab_1/3.cpp

@@ -0,0 +1,34 @@
+#include <iostream>
+#include <string>
+
+int print_fibo_until(int x)
+{
+    int n = 1;
+    int fibo_n = 1;
+    int fibo_previus = 0;
+
+    while(x >= fibo_n) 
+    {
+        std::cout << std::to_string(n) + std::to_string(fibo_n) + "\n";
+        int fibo_next = fibo_n + fibo_previus;
+        n++;
+        fibo_previus = fibo_n;
+        fibo_n = fibo_next;
+    }
+    return (x==fibo_previus);
+}
+
+int main()
+{
+    int y = 17711;
+    if(print_fibo_until(y))
+    {
+        std::cout << y;
+        std::cout << " is a Fibonacci number\n";
+    }
+    else
+    {
+        std::cout << y;
+        std::cout << " is not a Fibonacci number\n";
+    }
+}

lab_1/4.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+
+int main()
+{
+    std::cout << "Check size of datatypes:\n";
+    bool b;
+    std::cout << "bool:" + std::to_string(sizeof(b)) + "\n";
+    char c;
+    std::cout << "char:" + std::to_string(sizeof(c)) + "\n";
+    short s;
+    std::cout << "short:" + std::to_string(sizeof(s)) + "\n";
+    int i;
+    std::cout << "int:" + std::to_string(sizeof(i)) + "\n";
+    long l;
+    std::cout << "long:" + std::to_string(sizeof(l)) + "\n";
+    long long ll;
+    std::cout << "long long:" + std::to_string(sizeof(ll)) + "\n";
+    float f;
+    std::cout << "float:" + std::to_string(sizeof(f)) + "\n";
+    double d;
+    std::cout << "double:" + std::to_string(sizeof(d)) + "\n";
+    long double ld;
+    std::cout << "long double:" + std::to_string(sizeof(ld)) + "\n";
+}

lab_1/5.cpp

@@ -0,0 +1,21 @@
+#include <cmath>
+#include <iostream>
+
+double* get_unit_vec(double vector[3])
+{
+    double magnitude = std::sqrt(std::pow(vector[0], 2) + std::pow(vector[1], 2) + std::pow(vector[2], 2));
+    double *result = new double[3]{vector[0] / magnitude,vector[1] / magnitude,vector[2] / magnitude};
+    return result;
+}
+
+int main()
+{
+    std::cout << "Test the get_unit_vec funtion:\n";
+    double vector[3] = {4.0,6.0,8.0};
+    double *unit_vec = get_unit_vec(vector);
+    std::cout << "old x: " << vector[0] << " new x: " << unit_vec[0] << "\n";
+    std::cout << "old y: " << vector[1] << " new y: " << unit_vec[1] << "\n";
+    std::cout << "old z: " << vector[2] << " new z: " << unit_vec[2] << "\n";
+    std::cout << "old length: " << std::sqrt(std::pow(vector[0], 2) + std::pow(vector[1], 2) + std::pow(vector[2], 2)) <<" new length: " << std::sqrt(std::pow(unit_vec[0], 2) + std::pow(unit_vec[1], 2) + std::pow(unit_vec[2], 2)) << "\n";
+    delete[] unit_vec;
+}

lab_1/6.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+/*bool f(unsigned n)
+{
+    if(n == 'x') return true;
+    else return f(n - 256);
+}
+Under what conditions does the following function terminate and return a value?
+
+it terminates when you pass in the char 'x', otherwise you get a segmentationfault
+*/
+
+bool f(unsigned n)
+{
+    if(n == 'x') return true;
+    else return false;
+}
+
+int main()
+{
+    std::cout << "f('a')= "<< f('a') << "\n";
+    std::cout << "f('x')= "<< f('x') << "\n";
+}

lab_1/7.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <climits>
+//original function:
+long f(int n)
+{
+    if(n == 0) return 0;
+    else if(n < 0) return -f(-n);
+    else return f(n-1) + 3*n*(n-1);
+}
+
+//My implementation:
+long f2(int n)
+{   
+    long result = 0;
+    if(n<0)
+    { 
+        for (long i = 0; i<=n*-1; i++)
+        {
+            result += -(3*i*i-3*i);
+        }
+    }
+    else
+    {
+        for (long i = 0; i<=n; i++)
+        {
+            result += 3*i*i-3*i;
+        }
+    }
+    return result;
+}
+
+int main()
+{
+    //brute force check 😅:
+    for (int i = -20000; i != INT_MAX ; i++){
+        if(f(i) != f2(i))
+        {
+            std::cout << i << " WRONG!!😦 " << f(i) << " != "<< f2(i) << "\n";
+            /* Its seems like my implementation works well, until it reches the number 26756, there it 
+               outputs 19154179862460 instead of 19149884895164 and the error only gets worse from there.
+               I have no idea why this happens, and i dont have time to figure it out 🙃 
+               Please enlighten me if you can!
+            */
+            break;
+        }
+    }
+}

lab_1/makefile

@@ -0,0 +1,15 @@
+tasks:
+	g++ 1b-1.cpp 1b-2.cpp 1b.h -o task1b
+	g++ 3.cpp -o task3
+	g++ 4.cpp -o task4
+	g++ 5.cpp -o task5
+	g++ 6.cpp -o task6
+	g++ 7.cpp -o task7
+run:
+	$(info Name: Trygve)
+	./task1b
+	./task3
+	./task4
+	./task5
+	./task6
+	./task7