Calculate a penny triangle using node.js!

README.md

pen.js

How to use:

node pen.js width height pennies_per_stack pennies_removed_per_row

pen.js

"use strict"; // perfromance optimization

var num_width = process.argv[2];
var num_height = process.argv[3];
var num_stack = process.argv[4];
var num_dec = process.argv[5];

console.log('h:', num_height, 'w:', num_width, 'dec:', num_dec, 'stack:', num_stack);

if(!num_stack || !num_width || !num_height || !num_dec) {
  console.log('invalid input');
  process.exit(1); // bad error code
}

// scope & instancing
var num   = 0,
    total = 0;

console.time('main');
for(var i = 0; num !== 1; i++) {
  var nd_wi = num_dec*i; // calculate amount to subtract from difference * iteration
  var nh_wd = num_height-nd_wi; // calculate the height with difference
  var nw_wd = num_width-nd_wi; // calculate the width with difference

  var num = nw_wd*nh_wd; // get the area based on width and height
  var num_ws = num*num_stack // get the amount w/ the variable stack.

  total += num_ws; // add that layer to the total.
}


console.log('total is', total);
console.timeEnd('main');