From a9cbe6ea7dc7b39b19e279f4c91978a0cac33ac0 Mon Sep 17 00:00:00 2001
From: graapka99558 <graapka99558@th-nuernberg.de>
Date: Mon, 15 Dec 2025 15:22:41 +0100
Subject: [PATCH] (2)Parallel Basisversion erstellt

---
 CMakeLists.txt                      |  1 +
 parallel/matrizenmultiplikation.cpp | 50 +++++++++++++++++++++--------
 2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index efeaba9..c9276e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,3 +52,4 @@ if (APPLE)
     target_link_libraries(Prog3B "-framework Cocoa")
     target_link_libraries(Prog3B "-framework OpenGL")
 endif()
+
diff --git a/parallel/matrizenmultiplikation.cpp b/parallel/matrizenmultiplikation.cpp
index 2093cc2..e7d4a93 100644
--- a/parallel/matrizenmultiplikation.cpp
+++ b/parallel/matrizenmultiplikation.cpp
@@ -1,7 +1,7 @@
-
 #include <iostream>
 #include <vector>
 #include <chrono>
+#include <omp.h>
 
 
 // Funktion erzeugt zwei Matrizen A und B der Größe n x n mit Zufallswerten
@@ -27,17 +27,14 @@ void generateRandomMatrices(int n,
         }
 }
 
-// Matrizenmultiplikation
-std::vector<std::vector<double>> matmul(const std::vector<std::vector<double>>& A,
+std::vector<std::vector<double>> matmul_serial(
+    const std::vector<std::vector<double>>& A,
     const std::vector<std::vector<double>>& B)
 {
     int n = A.size();
     int m = B[0].size();
     int p = B.size();
 
-    if (A[0].size() != B.size())
-        throw std::runtime_error("Matrixgrößen passen nicht.");
-
     std::vector<std::vector<double>> C(n, std::vector<double>(m, 0.0));
 
     for (int i = 0; i < n; ++i)
@@ -48,22 +45,47 @@ std::vector<std::vector<double>> matmul(const std::vector<std::vector<double>>&
     return C;
 }
 
+std::vector<std::vector<double>> matmul_parallel(
+    const std::vector<std::vector<double>>& A,
+    const std::vector<std::vector<double>>& B)
+{
+    int n = A.size();
+    int m = B[0].size();
+    int p = B.size();
+
+    std::vector<std::vector<double>> C(n, std::vector<double>(m, 0.0));
+
+    #pragma omp parallel for
+    for (int i = 0; i < n; ++i)
+        for (int j = 0; j < m; ++j)
+            for (int k = 0; k < p; ++k)
+                C[i][j] += A[i][k] * B[k][j];
+
+    return C;
+}
+
 int main()
 {
     int N = 500;
-    std::vector<std::vector<double>> A, B;
 
+    std::vector<std::vector<double>> A, B;
     generateRandomMatrices(N, A, B);
 
+    // Serielle Version
     auto start = std::chrono::high_resolution_clock::now();
-    auto C_serial = matmul(A, B);
+    auto C_serial = matmul_serial(A, B);
     auto end = std::chrono::high_resolution_clock::now();
+    std::cout << "Serielle Laufzeit: "
+              << std::chrono::duration<double>(end - start).count()
+              << " Sekunden\n";
 
-    std::chrono::duration<double> duration = end - start;
-
-    std::cout << "Serielle Laufzeit bei " << N << "x" << N
-              << ": " << duration.count() << " Sekunden\n";
+    // Parallele Version
+    start = std::chrono::high_resolution_clock::now();
+    auto C_parallel = matmul_parallel(A, B);
+    end = std::chrono::high_resolution_clock::now();
+    std::cout << "Parallele Laufzeit: "
+              << std::chrono::duration<double>(end - start).count()
+              << " Sekunden\n";
 
     return 0;
-
-}
\ No newline at end of file
+}