/**********************************************************************************
  Dintr-un fisier text se citeste o matrice patratica. Sa se afiseze:
     a) numerele prime ale matricii intr-un alt fisier
     b) sa se scrie perechile de numere distincte aflate simetric fata de diagonala principala intr-un alt fisier text

  File:   test_matice.c
  Author: whatever
**********************************************************************************/


#include <stdio.h>
#include <stdlib.h>
#include <memory.h>

#define outfile_name1 "numere_prime.txt"
#define outfile_name2 "elemente_diagonale.txt"

int get_linecount(char* filename)
{
    FILE* local_file;
    char local_str[4096];
    char* read_ok;
    int line_count = 0;

    local_file = fopen(filename, "r");

    if (local_file == NULL)
    {
        printf("ERROR: file: \"%s\" could not be opened\n", filename);
        return -1;
    }

    while (1)
    {
        read_ok = fgets(local_str, 4096, local_file);
        if (!read_ok)
            break;
        line_count++;
    };

    fclose(local_file);
    return line_count;
}


int is_prime(int n,int f)
{
     if (n==f)
          return 1;
     if ((n%f==0) || (n==1))
          return 0;
     else
       return is_prime(n,f+1);
}

int main(int argc, char* argv[])
{
    FILE*  in_file;
    FILE*  out_file1;
    FILE*  out_file2;

    int line_count;
    int matrix[256][256];
    int i,j;

    if (argc != 2)
    {
        printf("Usage: test_matrice <in_file.txt>\n");
        return -1;
    }

    in_file = fopen(argv[1], "r");

    if (in_file == NULL)
    {
        printf("ERROR: in_file: \"%s\" could not be opened\n", argv[1]);
        return -1;
    }

    out_file1 = fopen(outfile_name1, "w+");

    if (out_file1 == NULL)
    {
        printf("ERROR: out_file: \"%s\" could not be created\n", outfile_name1);
        return -1;
    }

    out_file2 = fopen(outfile_name2, "w+");

    if (out_file2 == NULL)
    {
        printf("ERROR: out_file: \"%s\" could not be created\n", outfile_name2);
        return -1;
    }

    memset(matrix, 0, sizeof(int) * 128 * 128);


    line_count = get_linecount(argv[1]);
    printf("File \"%s\" has %d lines, assuming %dx%d matrix\n", argv[1], line_count,line_count,line_count);

    // read matrix into memory
    for (i=0; i<line_count; i++)
    {
        for (j=0; j<line_count; j++)
        {
            int number;
            fscanf(in_file, "%d", &number);
            matrix[i][j] = number;
        }
    };

/*
    // output matrix on display
    for (i=0; i<line_count; i++)
    {
        for (j=0; j<line_count; j++)
        {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    };
*/

    // save prime numbers to a file
    for (i=0; i<line_count; i++)
    {
        for (j=0; j<line_count; j++)
        {
            if (is_prime(matrix[i][j], 2))
                fprintf(out_file1, "%d ", matrix[i][j]);
        }
    };

    // save diagonally opposed numbers to a file
    for (i=0; i<line_count; i++)
    {
        for (j=0; j<line_count; j++)
        {
            if ((i>j) && (matrix[i][j] != matrix[j][i]))
            {
                fprintf(out_file2, "%d %d\n", matrix[i][j], matrix[j][i]);
            }
        }
    };

    fclose(in_file);
    fclose(out_file1);
    fclose(out_file2);

    return 1;
}