// file: my first program
//
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

// function: myprint
//
// arguments:
//  FILE* fp: open file pointer
//  float* x: a floating point array
//  long N: the total number of elements
//
// return: a logical value indicating status
//
bool myprint(FILE* fp_a, float* x_a, long N_a) {

  // print
  //
  for (long i = 0; i < N_a; i++) {
    fprintf(stdout, "myprint: (%d) = %f\n", i, x_a[i]);
  }

  // exit gracefully
  //
  return true;
}

// function: mychange
//
// arguments:
//  float* x: a floating point array
//  long N: the total number of elements
//
// return: a logical value indicating status
//
bool mychange(float* x_a, long N_a) {

  // loop over the matrix
  //
  for (long i = 0; i < N_a; i++) {
      *x_a++ = (float)27.0;
  }

  // exit gracefully
  //
  return true;
}

// function: mycopy
//
// arguments:
//  float* x: a floating point array
//  long N: the total number of elements
//
// return: a float* containing the new array
//
float* mycopy(float* x_a, long N_a) {

  // allocate memory
  //
  //  float* rval = malloc(N_a * sizeof(float));
  float* rval = new float[N_a];

  // create a temp pointer
  //
  float* tmp_val = rval;

  // copy the data:
  //  we could use memcpy()
  //
  //  memcpy(rval, x_a, N_a * sizeof(float));
  for (long i = 0; i < N_a; i++) {
    *tmp_val++ = *x_a++;
  }

  // exit gracefully
  //
  return rval;
}

// my main program starts here
//
int main(int argc, char** argv) {

  // grab the dimensions from the command line
  //
  long Mrows = atoi(argv[1]);
  long Ncols = atoi(argv[2]);
  long Pdepth = atoi(argv[3]);

  // declare an array of floats
  //
  float x[Mrows][Ncols][Pdepth];

  // set the values
  //

  for (long m = 0; m < Mrows; m++) {
    for (long n = 0; n < Ncols; n++) {
      for (long p = 0; p < Pdepth; p++) {
	x[m][n][p] = (float)(m + n + p);
	fprintf(stdout, "[%d][%d][%d] = %f\n", m, n, p, x[m][n][p]);
      }
    }
  }

  float* ptr = (float*)x;
  fprintf(stdout, "the memory location is %u\n", x);
  fprintf(stdout, "data: \n");
  for (long i = 0; i < Mrows * Ncols * Pdepth; i++) {
    fprintf(stdout, "(%d: %u): %f\n", i, ptr, *ptr);
    ptr++;
  }
  
  // print x
  //
  myprint(stdout, (float*)x, Mrows * Ncols * Pdepth);

  // change x
  //
  mychange((float*)x, Mrows * Ncols * Pdepth);
  fprintf(stdout, "New values:\n");
  myprint(stdout, (float*)x, Mrows * Ncols * Pdepth);

  // create a new array
  //
  float* y = mycopy((float*)x, Mrows * Ncols * Pdepth);
  fprintf(stdout, "Copied values:\n");  
  myprint(stdout, (float*)y, Mrows * Ncols * Pdepth);
  delete [] y;

  /*
  long M = 10;
  float* y = new float[M*M];
  memset(y, 0, M*M*sizeof(float));
  y[M*1 + 1] = 27.0; y[M*2 + 2] = 99.0;

  float*z = y;
  long N = 3;
  for (long i = 0; i < N; i++) {
    for (long j = 0; j < N; j++) {
      fprintf(stdout, "y[%d][%d] = (%u) %f <> %u %f\n", i, j, &y[N*i+j],
	      y[N*i+j], z, *z);
      z++;
    }
  }

  /*
  short int buf[10];
  FILE* fp = fopen(argv[1], "r");
  fprintf(stdout, "position = %u\n", ftell(fp));
  fread(buf, sizeof(short int), 1, fp);
  fprintf(stdout, "position = %u\n", ftell(fp));
  fclose(fp);

  /*
  void* pstr = (void*)new char[10];

  char Joe[] = "JoePicone";
  char* str = Joe;
  fprintf(stdout, "str = %c\n", str[0]);
  str++;
  fprintf(stdout, "str = %c\n", *str);

  double Mary[10]; Mary[0] = 27.0; Mary[1] = 35.0; Mary[2] = -27.0;
  double* psum = (double*)Mary;
  fprintf(stdout, "psum = %f\n", *psum);
  psum++;
  fprintf(stdout, "psum = %f\n", *psum);
  */

  // exit gracefully
  //
  return 0;
}