#include <stdio.h>
#include <stdlib.h>
int read_array(const char *name, double *a, unsigned int n);
void print_array(double *a, unsigned int n);
int f(double *a, unsigned int n);

/* Ф-ия возвращает 1, если масиив симметричный. 0, если нет.*/
int f(double *a, unsigned int n)
{
    unsigned int i;

    for( i = 0; i<n/2; i++ )
    {
        if( a[i]!=a[n - 1 - i] )
            return 0;
    }

    return 1;
}

void print_array(double *a, unsigned int n)
{
    unsigned int i;

    for( i = 0; i<n; i++ )
        printf("a[%u]==%lf\t", i, a[i]);

    printf("\n");
}

int read_array(const char *name, double *a, unsigned int n)
{
    FILE *input;
    unsigned int i;

    if( !(input = fopen(name, "r")) ) return -1;

    for( i = 0; i<n; i++ )
    {
        if( fscanf(input, "%lf", a + i)!=1  )
        {
            fclose(input);
            return -2;
        }
    }

    fclose(input);
    return 0;
}

int main(int argc, const char *argv[])
{
    unsigned int n;
    int res;
    double *a;

    if( (argc!=3) || (sscanf(argv[1], "%u", &n)!=1) )
    {
        fprintf(stderr, "Usage: %s [length] [file]\n", argv[0]);
        return -1;
    }

    a = (double *)malloc(n*sizeof(double));
    if( !a )
    {
        fprintf(stderr, "Not enough memory!\n");
        return -2;
    }

    res = read_array(argv[2], a, n);
    if( res<0 )
    {
        switch(res)
        {
        case -1:
            fprintf(stderr, "Can not open %s\n", argv[2]);
            return 0;
        case -2:
            fprintf(stderr, "Can not read %s\n", argv[2]);
            return 0;
        default:
            fprintf(stderr, "Unknown error %d in %s\n", res, argv[2]);
            return 0;
        }
    }

    printf("f() returned %d\n", f(a, n));

    print_array(a, n);

    return 0;
}