initial commit

labs/1/Main.java

@@ -0,0 +1,144 @@
+import java.util.Objects;
+
+public class Main {
+    public static void main(String[] args) {
+        byte a = 1, b = 1, n = 10, m = 10;
+        boolean simplify_math = true;
+        int iteration_amount = 1;
+        byte verbosity = 1;
+        int p = 0;
+        boolean run_safe = false;
+
+        while (p < args.length) {
+            try {
+            if (Objects.equals(args[p], "-h")) {
+                System.out.print("Usage: java Main [options]\nOptions:\n    -v <byte>   Sets verbosity level (0-2, default is 1\n    -a, -b, -n, -m <byte>   Sets default values for a, b, n and m variables respectively\n    -s <bool>   Use simplified algorithm to calculate the desired value (true/false, default is true)\n    -t <int>    Enables benchmarking mode and performs selected calculation <int> times\n");
+                System.exit(0);
+            }
+            else if (Objects.equals(args[p], "-v")) {
+                verbosity = (byte) Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-a")) {
+                a = (byte) Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-b")) {
+                b = (byte) Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-n")) {
+                n = (byte) Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-m")) {
+                m = (byte) Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-t")) {
+                iteration_amount = Integer.parseInt(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "-s")) {
+                simplify_math = Boolean.parseBoolean(args[p+1]);
+                p += 2;
+            }
+            else if (Objects.equals(args[p], "--safe")) {
+                run_safe = true;
+                p++;
+            }
+            else {
+                if (verbosity >= 1) {
+                    System.err.println("Unknown argument found: " + args[p] + "\nPlease, use 'java Main -h' for help");
+                }
+                System.exit(1);
+            }
+            }
+            catch (Exception e) {
+                System.err.println("Exception while parsing CLI arguments: " + e);
+                System.err.println("Aborting execution.");
+                System.exit(1);
+            }
+        }
+
+        if (verbosity >= 2) {
+            System.out.println(String.format("Using arguments: a=%d, b=%d, n=%d, m=%d", a, b, n, m));
+        }
+
+        if (simplify_math == true) {
+            if (b <= 0 && m >= 0) {
+                System.err.println("Preventing division by zero!\nAborting calculations.");
+                System.exit(1);
+            }
+            else
+            {
+                if (a <= 0 && n >= 0) {
+                    System.err.println("Bypassing division by zero with fast math; expect wrong calculations");
+                    if (run_safe) {
+                        System.err.println("--safe flag is set, preventing further execution");
+                        System.exit(1);
+                    }
+                }
+
+                for (int g = 0; g < iteration_amount; g++) {
+                    double result = calc_quick(verbosity, a, n, b, m);
+                    if (iteration_amount == 1) {
+                        if (verbosity >= 1) {
+                            System.out.println(String.format("Result is %.3f", result));
+                        }
+                        else
+                        {
+                            System.out.print(result);
+                        }
+                    }
+                }
+            }
+        }
+        else
+        {
+            if ((a <= 0 && n >= 0) || (b <= 0 && m >= 0)) {
+                System.err.println("Preventing division by zero!\nAborting calculations.");
+                System.exit(1);
+            }
+            else
+            {
+                for (int g = 0; g < iteration_amount; g++) {
+                    double result = calc_generic(verbosity, a, n, b, m);
+                    if (iteration_amount == 1) {
+                        if (verbosity >= 1) {
+                            System.out.println(String.format("Result is %.3f", result));
+                        }
+                        else
+                        {
+                            System.out.print(result);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private static double calc_generic(byte verbosity, byte a, byte n, byte b, byte m) {
+        double result = 0;
+        for (byte i = a; i <= n; i++) {
+            for (byte j = b; j <= m; j++) {
+                if (verbosity >= 3) {
+                    System.out.print(result);
+                }
+
+                result += ((double) i / (double) j) / ((double) i - (double) 0);
+
+                if (verbosity >= 3) {
+                    System.out.println(" + " + (((double)i / (double)j) / ((double)i-(double)0)) + " = " + result);
+                }
+            }
+        }
+        return result;
+    }
+
+    private static double calc_quick(byte verbosity, byte a, byte n, byte b, byte m) {
+        double t = 0;
+        for (byte j = b; j <= m; j++) {if (verbosity >= 3) {System.out.print(t);}; t += (double)1/(double)j; if (verbosity >= 3) {System.out.println(" + " + (double)1/(double)j + " = " + t);} }
+        return (double) (t * ((double)n-(double)a + (double) 1));
+    }
+}

labs/1/benchmark.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+time -f 'Non-optimal: %U %S' java Main -v 1 -t 10000000 -s false
+time -f '    Optimal: %U %S' java Main -v 1 -t 10000000 -s true

labs/1/check.py

@@ -0,0 +1,9 @@
+#!/bin/python3
+
+import os
+
+for i in range(-5, 11):
+    print(f"Current test: {i}")
+    os.system(f"java Main -s false -a {i}")
+    os.system(f"java Main -s true -a {i}")
+    print()