#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <omp.h>

const char         Literals[]    = "0123456789";
const unsigned int NLiterals     = sizeof( Literals ) - 1;
const char         TestString[]  = "4877";
char               EndString[16];

void parallel_function( int, int * );

int main()
{
    int flag = -1;
    int count = 0;

    #pragma omp parallel default( none ) shared( flag ) reduction( +:count )
    {
        while( flag < 0 )
        {
            parallel_function( count, &flag );
            count++;
        }
    }

    if( !flag )
        printf( "Nothing found!!! %i tries\n", count );

    else
        printf( "Match: %s ! Tries: %i\n",  EndString, count );

    return 0;
}

void parallel_function( int count, int *flag )
{
    char str[10];
    int  c = count;

    if( ( *flag ) >= 0 )
        return;

    memset( str, 0, sizeof( str ) );

    // Compute the string from the value of 'c'. Each different
    // count will give a unique solution.
    int length = ( c % 5 ) + 1;
    c /= 5;

    for( int n = 0; n < length; n++ )
    {
        str[n] = Literals[c%NLiterals];
        c /= NLiterals;
    }

    // If and only if we have the correct solution, store the value.
    if( strncmp( TestString, str, sizeof( TestString ) ) == 0 )
    {
        strncpy( EndString, str, strlen( str ) );
        ( *flag ) = count;
    }
}