OpenMP expected declaration or statement at end of input

Question

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <omp.h>
#include <sys/time.h>


#define N 10000

int A[N][N];
int B[N][N];
int C[N][N];

int main(){

    int i,j,k;
    struct timeval tv1, tv2;
    struct timezone tz;
    double elapsed;
    for (i= 0; i< N; i++){
        for (j= 0; j< N; j++)
        {
            A[i][j] = 3;
            B[i][j] = 3;
        }
    }
    gettimeofday(&tv1, &tz);
    omp_set_num_threads(4);
    #pragma omp parallel default (private) shared (A,B,C,N) num_threads(4) 
    #pragma omp parallel for schedule(static)
    for (i = 0; i < N; ++i){
        for (j = 0; j < N; ++j){
            C[i][j]=0;
            for (k = 0; k < N; ++k){
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }


    gettimeofday(&tv2, &tz);
    elapsed = (double) (tv2.tv_sec-tv1.tv_sec) + (double) (tv2.tv_usec-tv1.tv_usec) * 1.e-6;
    printf("elapsed time = %f seconds.\n", elapsed);

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

this code is not working , although I make sure that every "{" is put right ! what's wrong with this code? It is a matrix multiplication using OpenMp library , and I am using eclipse c++ Any idea of what's wrong with the code? I get "expected declaration or statement at end of input } " and it glows under printf("\n"); I tried to delete the whole thing that prints the matrix but it didn't work

Answer 1

I got following errors on Wandbox:

prog.c: In function 'main':
prog.c:29:35: error: expected 'none' or 'shared' before 'private'
   29 |     #pragma omp parallel default (private) shared (A,B,C,N) num_threads(4)
      |                                   ^~~~~~~
prog.c:29:58: error: expected ')' before numeric constant
   29 |     #pragma omp parallel default (private) shared (A,B,C,N) num_threads(4)
      |                                                   ~      ^
      |                                                          )

Firstly, OpenMP default clause doesn't have option private. You should remove the default clause and mark the inner loop variables j and k private via private clause.

Secondly, N is defined as macro and is expanded to 10000. It is not a variable and therefore it cannot be specified in OpenMP clause that expect variables.