Project Euler.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# #1 - Multiples of 3 and 5\n",
    "\n",
    "\n",
    "\n",
    "If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.\n",
    "\n",
    "Find the sum of all the multiples of 3 or 5 below 1000.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Below 10 => 23\n",
      "Below 1000 => 233168\n"
     ]
    }
   ],
   "source": [
    "# It's just a matter of getting through all integer from 0 to N and checking if the modulo is 0\n",
    "\n",
    "def sum_of_multiple_3_and_5(upper_bound):\n",
    "    stored_multiple = []\n",
    "    for i in range(upper_bound):\n",
    "        if not i % 3:\n",
    "            stored_multiple.append(i)\n",
    "        elif not i %5:\n",
    "            stored_multiple.append(i)\n",
    "    return sum(stored_multiple)\n",
    "\n",
    "print(\"Below 10 => {sm10}\".format(sm10=sum_of_multiple_3_and_5(10)))\n",
    "print(\"Below 1000 => {sm1000}\".format(sm1000=sum_of_multiple_3_and_5(1000)))\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# #2 - Even Fibonacci numbers\n",
    "Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:\n",
    "\n",
    "1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...\n",
    "\n",
    "By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Sum of even Fibonacci<400000 => 4613732\n"
     ]
    }
   ],
   "source": [
    "#I'm going forward and calc the sum along the way\n",
    "two_before = 1\n",
    "one_before = 2\n",
    "sum_even = 2\n",
    "\n",
    "while one_before < 4000000:\n",
    "    last = one_before + two_before\n",
    "    if not last % 2:\n",
    "        sum_even += last\n",
    "    two_before = one_before\n",
    "    one_before = last\n",
    "\n",
    "print(\"Sum of even Fibonacci<400000 => \"+ str(sum_even))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# #3 Largest prime factor\n",
    "\n",
    "The prime factors of 13195 are 5, 7, 13 and 29.\n",
    "\n",
    "What is the largest prime factor of the number 600851475143 ?\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": []
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.6.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}