mm.cpp

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <assert.h>
#include <omp.h>
using namespace std;

int main()
{
    int i, j, k, n;
    double temp, start, end, run;

    cout << "Dimensión de la matriz ('N' para NxN) (2-5000): ";
    cin >> n;

    assert( n >= 2 && n <= 5000 );

  int **A = 0;
  int **B = 0;
  double **C = 0;

//memory allocated for elements of rows.
A = new int *[n];
B = new int *[n];
C = new double *[n];

//memory allocated for  elements of each column.
for( int i = 0 ; i < n ; i++ )
  {
   A[i] = new int[n];
   B[i] = new int[n];
   C[i] = new double[n];
  }


   cout <<"Generando arreglo con valores random...\n";
   srand( time(NULL) );

    for(i=0; i<n; ++i) {
        for(j=0; j<n; ++j)
         {
            A[i][j] = (rand() % n);
            B[i][j] = (rand() % n);
         }
    }
    cout <<"Arreglos completados.\n";

/*
     // showing the matrix on the screen

    for(int x=0;x<n;x++)  // loop 3 times for three lines
    {
        for(int y=0;y<n;y++)  // loop for the three elements on the line
        {
            cout<<A[x][y] << "\t";  // display the current element out of the array
        }
    cout<<endl;  // when the inner loop is done, go to a new line
    }

   cout << endl;

     // showing the matrix on the screen

    for(int x=0;x<n;x++)  // loop 3 times for three lines
    {
        for(int y=0;y<n;y++)  // loop for the three elements on the line
        {
            cout<<B[x][y] << "\t";  // display the current element out of the array
        }
    cout<<endl;  // when the inner loop is done, go to a new line
    }
 */


 //Multiplicacion
  cout << "Multiplicando con OMP...\n";
//  fflush(stdout);
  start = omp_get_wtime();

//#pragma omp parallel for private(i, j, k, temp)
      for(i=0; i<n; ++i) {
        for(j=0; j<n; ++j) {
            temp = 0;
            for(k=0; k<n; ++k) {
                temp += A[i][k] * B[k][j];
            }
            C[i][j] = temp;
        }
    }

    end = omp_get_wtime();
    cout << "Le tomó "<< end-start << "segundos.\n";

 /*
  cout << endl;
  for(int x=0;x<n;x++)  // loop 3 times for three lines
    {
        for(int y=0;y<n;y++)  // loop for the three elements on the line
        {
            cout<<C[x][y] << "\t";  // display the current element out of the array
        }
    cout<<endl;  // when the inner loop is done, go to a new line
    }

*/


    return 0;  // return 0 to the OS.
}