#include "stdio.h"
#include <iostream>
#include "math.h"

using namespace std;
double  output ( double input1, double input2 ); //ignore this at first

int main ( int argc, char** argv ) {
  
  //today's lesson #1: variable declarations and storage review; quick ops
  // do not copy my comment statements today!
  double a; int b; float c; //allowed to put multiple lines on one with ;
  double beta = 0.1; //beta created and value stored, until it gets changed
  a = (beta * 8. - 1.) / 3.; //variables can be used in equations. Periods optional
  b = 1; b++; b--; //same as b += 1 and b -= 1 which are same as b=b+1 and b=b-1
  a /= 3.; a *= 4.; //same as a = a/3 and a = a*4
  
  //lesson #2: arrays, 2D and higher
  double position[3];
  position[0] = 2.7; //arrays start at 0 NOT 1 in C/C++ (argv is only exception!)
  position[1] = 3.1;
  position[2] = 1.6; //if you try to access element [3] you would get a seg fault
  int cool_numbers[4] = { 5, 6, 7, 8 };
  float MatricesAreFun[9][5];

  //lesson #3: commenting out entire code blocks
  /*if ( a < 0 ) {
    fprintf(stderr,"I don't like your numbers!\n");
  }
  else if ( a == 0 ) {
    cout << "Argh, zero!!" << endl;
  }
  else {
    cout << "You are awesome!" << endl;
  }*/

  //lesson #4: the switch statement (vs. if/else)
  switch ( b ) { //expression inside () must be an integer or equivalent
  case -1: //this is the value of the integer b being checked
    cout << "Cold!" << endl;
    break; //break tells it to stop checking the rest
  case 0:
    cout << "Neutral!" << endl;
    break;
  case 1: //you can have as many cases as you would like
    cout << "Hot!" << endl;
    break;
  default: //default case recommended. It's like an else. No break needed.
    cout << "WTH?!" << endl;
  }
  
  //lesson #5: function calls
  double yo = output(2.,3.);
  cout << yo << "\t" << endl;
  
  //Next time: rand's, loops, debugging, file reading, strings
  return 1;

}

double output ( double input1, double input2 ) {
  
  double spitOut = input1 * 2. + input2; //could separate out
  return spitOut; //something was done to input, then new result returned
  
}