Merge remote-tracking branch 'origin/master'

parallele_zeilenverlegung.cpp

@@ -2,43 +2,36 @@
 #include <chrono>
 #include <iostream>
 #include <omp.h>
+#include <cstdlib>
+#include <ctime>
 
-// Funktion erzeugt zwei Matrizen A und B der Größe n x n mit Zufallswerten
+// Zufallsmatrizen erzeugen
 void generateRandomMatrices(int n,
                             std::vector<std::vector<double>>& A,
-                            std::vector<std::vector<double>>& B,
-                            double min_val = 0.0,
-                            double max_val = 10.0)
+                            std::vector<std::vector<double>>& B)
 {
-    // Zufallsgenerator initialisieren
     std::srand(static_cast<unsigned int>(std::time(nullptr)));
-
     A.resize(n, std::vector<double>(n));
     B.resize(n, std::vector<double>(n));
 
     for (int i = 0; i < n; ++i)
         for (int j = 0; j < n; ++j)
         {
-            double r1 = static_cast<double>(std::rand()) / RAND_MAX; // 0..1
-            double r2 = static_cast<double>(std::rand()) / RAND_MAX; // 0..1
-            A[i][j] = min_val + r1 * (max_val - min_val);
-            B[i][j] = min_val + r2 * (max_val - min_val);
+            A[i][j] = static_cast<double>(rand()) / RAND_MAX * 10.0;
+            B[i][j] = static_cast<double>(rand()) / RAND_MAX * 10.0;
         }
 }
 
-// Matrizenmultiplikation
-std::vector<std::vector<double>> matmul(const std::vector<std::vector<double>>& A,
+// Serielle Matrizenmultiplikation
+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));
-#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)
@@ -47,22 +40,55 @@ std::vector<std::vector<double>> matmul(const std::vector<std::vector<double>>&
     return C;
 }
 
+// Parallele Zeilenzerlegung
+std::vector<std::vector<double>> matmul_row_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)      // Zeilen parallel
+        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; // z.B. 500x500
+    int N = 500;
     std::vector<std::vector<double>> A, B;
-
-    auto start = std::chrono::steady_clock::now();
-
     generateRandomMatrices(N, A, B);
-    auto C_serial = matmul(A, B);
 
+    // Serielle Version
+    auto start = std::chrono::steady_clock::now();
+    auto C_serial = matmul_serial(A, B);
     auto end = std::chrono::steady_clock::now();
-    std::chrono::duration<double> diff = end - start;
-    std::cout << "Took: " << diff.count() << "s\n";
+    std::cout << "Serial multiplication took: "
+              << std::chrono::duration<double>(end - start).count() << "s\n";
 
+    // Zeilenparallel
+    start = std::chrono::steady_clock::now();
+    auto C_row = matmul_row_parallel(A, B);
+    end = std::chrono::steady_clock::now();
+    std::cout << "Row-parallel multiplication took: "
+              << std::chrono::duration<double>(end - start).count() << "s\n";
+
+    // Vergleich
+    for (int i = 0; i < N; ++i)
+        for (int j = 0; j < N; ++j)
+            if (C_serial[i][j] != C_row[i][j])
+            {
+                std::cout << "Mismatch at " << i << "," << j << "\n";
+                return 1;
+            }
+
+    std::cout << "All results match!\n";
     return 0;
 }
-//
-// Created by Anke Bidlingmaier on 15.12.25.
-//