to be ignored, task 4b

src/thread.cpp

@@ -0,0 +1,125 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <fstream>
+#include <thread>
+#include <chrono>
+#include <numeric>
+
+bool readFile(const std::string& filename, std::vector<int>& data) {
+    std::ifstream file(filename);
+
+    if (!file.is_open()) {
+        std::cerr << "FEHLER: Konnte Datei nicht oeffnen!\n";
+        std::cerr << "Pfad: " << filename << "\n";
+        return false;
+    }
+
+    int value;
+    std::cout << "Lese Datei ein... (Pfad: " << filename << ")\n";
+
+    while (file >> value) {
+        data.push_back(value);
+    }
+
+    file.close();
+    return true;
+}
+
+int main() {
+    std::vector<int> messungen;
+    std::string pfad = "C:\\Users\\Bruno\\Desktop\\BME\\BME 3\\PROG B\\praktikum\\thread\\measurements.txt";
+
+    if (!readFile(pfad, messungen)) {
+        std::cout << "\nDruecke ENTER zum Beenden...";
+        std::cin.get();
+        return 1;
+    }
+
+    if (messungen.size() < 2) {
+        std::cout << "Datei ist leer oder hat zu wenig Werte!\n";
+        std::cin.get();
+        return 0;
+    }
+
+    std::cout << "Erfolg! " << messungen.size() << " Messwerte geladen.\n";
+    std::cout << "-----------------------------------\n";
+
+    {
+        std::cout << "Starte serielle Berechnung...\n";
+        auto start = std::chrono::steady_clock::now();
+
+        long long increases = 0;
+        for (size_t i = 1; i < messungen.size(); i++) {
+            if (messungen[i] > messungen[i - 1]) {
+                increases++;
+            }
+        }
+
+        auto end = std::chrono::steady_clock::now();
+        std::chrono::duration<double> diff = end - start;
+
+        std::cout << "[SERIELL]  Anstiege: " << increases << "\n";
+        std::cout << "           Zeit:     " << diff.count() << " s\n\n";
+    }
+
+    {
+        std::cout << "Starte parallele Berechnung...\n";
+        auto start = std::chrono::steady_clock::now();
+
+        unsigned int numThreads = std::thread::hardware_concurrency();
+        if (numThreads == 0) numThreads = 4;
+
+        std::vector<std::thread> threads;
+        std::vector<long long> results(numThreads, 0);
+
+        size_t totalComparisons = messungen.size() - 1;
+        size_t base = totalComparisons / numThreads;
+        size_t remainder = totalComparisons % numThreads;
+
+        size_t idx = 1;
+
+        for (unsigned int t = 0; t < numThreads; t++)
+        {
+            size_t startIdx = idx;
+            size_t count = base + (t < remainder ? 1 : 0);
+            size_t endIdx = idx + count - 1;
+
+            idx = endIdx + 1;
+
+            threads.emplace_back([&, t, startIdx, endIdx]() {
+                long long localCount = 0;
+                if (startIdx < messungen.size()) {
+                    for (size_t i = startIdx; i <= endIdx; ++i) {
+                        if (messungen[i] > messungen[i - 1]) {
+                            ++localCount;
+                        }
+                    }
+                }
+                results[t] = localCount;
+            });
+        }
+
+        for (auto& th : threads) {
+            if (th.joinable())
+                th.join();
+        }
+
+        long long totalParallel = 0;
+        for (long long r : results) {
+            totalParallel += r;
+        }
+
+        auto end = std::chrono::steady_clock::now();
+        std::chrono::duration<double> diff = end - start;
+
+        std::cout << "[PARALLEL] Anstiege: " << totalParallel << " (Threads: " << numThreads << ")\n";
+        std::cout << "           Zeit:     " << diff.count() << " s\n";
+    }
+
+    std::cout << "\n-----------------------------------\n";
+    std::cout << "Druecke ENTER zum Beenden...";
+    std::cin.get();
+
+    return 0;
+}