added problem 17 in py

python/Problem_17.ipynb

@@ -0,0 +1,91 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "collapsed": true
+   },
+   "source": [
+    "### Problem 17: Number letter counts"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "I'm not very keen on char-dependent tasks, so I'll try to implement the task obviosly:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "21124\nTook  0.0037851333618164062\n"
+     ]
+    }
+   ],
+   "source": [
+    "import time\n",
+    " \n",
+    "start = time.time()\n",
+    " \n",
+    "S = [0,3,3,5,4,4,3,5,5,4,3,6,6,8,8,7,7,9,8,8]\n",
+    "D = [0,3,6,6,5,5,5,7,6,6]\n",
+    "H = 7\n",
+    "T = 8\n",
+    " \n",
+    "total = 0\n",
+    "for i in range(1,1000):\n",
+    "    c = i % 10 \n",
+    "    b = ((i % 100) - c) / 10 \n",
+    "    a = ((i % 1000) - (b * 10) - c) / 100 \n",
+    " \n",
+    "    if a != 0:\n",
+    "        total += S[int(a)] + H \n",
+    "        if b != 0 or c != 0: total += 3 \n",
+    "    if b == 0 or b == 1: total += S[int(b * 10 + c)]\n",
+    "    else: total += D[int(b)] + S[c]\n",
+    " \n",
+    "total += S[1] + T\n",
+    "finish = time.time() - start\n",
+    " \n",
+    "print(total)\n",
+    "\n",
+    "print(\"Took \", finish)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "If we'll not think about number of letters/days/etc and simply take the range, than the complexity is O(N)."
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2.0
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.6"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}