24.9.2016.3.c

// 24. 9. 2016 (3)

#include <stdio.h>
#include <mpi.h>
#define W MPI_COMM_WORLD

int main(int argc, char** argv) {

  MPI_Init(&argc, &argv);
  int m = 3;
  int n = 2;
  int k = 6;
  int s = 2;
  int A[m][n], B[n][k], C[m][k];
  int locB[n][s], locC[m][s];
  int rank, size;
  MPI_Datatype MPI_COLUMN_OLD;
  MPI_Datatype MPI_COLUMN;

  MPI_Comm_rank(W, &rank);
  MPI_Comm_size(W, &size);

  if (rank == 0) {
    printf("\n===A===\n");
    for (int i = 0; i < m; i++) {
      for (int j = 0; j < n; j++) {
        A[i][j] = (i - j);
        printf("%2d ", A[i][j]);
      }
      printf("\n");
    }
    printf("\n===B===\n");
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < k; j++) {
        B[i][j] = i - j;
        printf("%2d ", B[i][j]);
      }
      printf("\n");
    }
    printf("\n");
    printf("\n");
  }

  MPI_Type_vector(n, s, k, MPI_INT, &MPI_COLUMN_OLD);
  MPI_Type_create_resized(MPI_COLUMN_OLD, 0, s * sizeof(int), &MPI_COLUMN);
  MPI_Type_commit(&MPI_COLUMN);

  MPI_Bcast(A, m * n, MPI_INT, 0, W);
  MPI_Scatter(B, 1, MPI_COLUMN, locB, s * n, MPI_INT, 0, W);

  for (int i = 0; i < m; i++) {
    for (int ii = 0; ii < s; ii++) {
      locC[i][ii] = 0;
      for (int iii = 0; iii < n; iii++) {
        locC[i][ii] += A[i][iii] * locB[iii][ii];
      }
    }
  }

  for (int i = 0; i < m; i++) {
    for (int j = 0; j < s; j++) {
      printf("[%d] %3d\t", rank, locC[i][j]);
    }
    printf("\n");
  }
  printf("\n");

  struct {
    int value;
    int index;
  } locMin;
  locMin.value = locB[0][0];
  locMin.index = rank;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < s; j++) {
      if (locB[i][j] < locMin.value) {
        locMin.value = locB[i][j];
      }
    }
  }
  printf("Najmanji u %d je %d.\n", locMin.index, locMin.value);

  struct {
    int value;
    int index;
  } min;
  MPI_Reduce(&locMin, &min, 1, MPI_2INT, MPI_MINLOC, 0, W);
  MPI_Bcast(&min, 1, MPI_2INT, 0, W);
  int root = min.index;
  if (rank == root) {
    printf("{%d} Najmanji ukupno je %d s indeksom %d.\n", rank, min.value, min.index);
  }

  int tempC[m * k];
  MPI_Gather(locC, m * s, MPI_INT, tempC, m * s, MPI_INT, root, W);

  if (rank == root) {
    int w = 0;
    for (int b = 0; b < k/s; b++) {
      for (int i = 0; i < m; i++) {
        for (int j = s * b; j < s * b + s; j++) {
          C[i][j] = tempC[w++];
        }
      }
    }

    for (int i = 0; i < m; i++) {
      for (int j = 0; j < k; j++) {
        printf("%3d\t", C[i][j]);
      }
      printf("\n");
    }
    printf("\n");
  }

  MPI_Finalize();
  return 0;

}