gigimushroom · Aug 18, 2020 · Aug 19, 2020 · Aug 22, 2020 · Aug 27, 2020 · Aug 28, 2020
Showing 343 changed files with 108,919 additions and 35 deletions.
diff --git a/advance/python/Calculator Implementation.ipynb b/advance/python/Calculator Implementation.ipynb
@@ -0,0 +1,134 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Support cases\n",
+    "\n",
+    "`((2+3)*5)`\n",
+    "\n",
+    "`(3+(10/2))`"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 31,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "10\n",
+      "18\n",
+      "4\n"
+     ]
+    }
+   ],
+   "source": [
+    "symbols = ['+', '-', '*', '/']\n",
+    "\n",
+    "\n",
+    "def tokenizer(str):\n",
+    "    tokens = []\n",
+    "    rhs = ''\n",
+    "    for i in range(len(str)):\n",
+    "        if str[i] == '(' or str[i] == ')' or str[i] in symbols:\n",
+    "            # We got left hand side, save it.\n",
+    "            if rhs:\n",
+    "                tokens.append(rhs)\n",
+    "                rhs = ''\n",
+    "            tokens.append(str[i])\n",
+    "            \n",
+    "        else:\n",
+    "            rhs += str[i]\n",
+    "            \n",
+    "    return tokens\n",
+    "\n",
+    "def calc(tokens):\n",
+    "    lhs = tokens[0]\n",
+    "    sym = tokens[1]\n",
+    "    rhs = tokens[2]\n",
+    "    if sym == '+':\n",
+    "        return int(lhs) + int(rhs)\n",
+    "    elif sym == '-':\n",
+    "        return int(lhs) - int(rhs)\n",
+    "    elif sym == '*':\n",
+    "        return int(lhs) * int(rhs)\n",
+    "    elif sym == '/':\n",
+    "        return int(lhs) / int(rhs)\n",
+    "    \n",
+    "    return None\n",
+    "\n",
+    "def eval(tokens):\n",
+    "    if len(tokens) == 1:\n",
+    "        return tokens[0]\n",
+    "    \n",
+    "    return parser(tokens)\n",
+    "\n",
+    "def parser(tokens):\n",
+    "    # Trim ().\n",
+    "    tokens = tokens[1:-1]\n",
+    "    \n",
+    "    paren_start = False\n",
+    "    for i, t in enumerate(tokens):\n",
+    "        if t == '(':\n",
+    "            paren_start = True\n",
+    "            \n",
+    "        elif t == ')':\n",
+    "            paren_start = False\n",
+    "            # We got LHS in (xxx), next symbol is +/-/*//, add these as tokens\n",
+    "            symbol = tokens[i+1]\n",
+    "            lhs = eval(tokens[:i+1])\n",
+    "            rhs = eval(tokens[i+2:])\n",
+    "            #print(lhs, symbol, rhs)\n",
+    "            tks = [lhs, symbol, rhs]\n",
+    "            return calc(tks)\n",
+    "            \n",
+    "        elif t in symbols and not paren_start:\n",
+    "            symbol = t\n",
+    "            lhs = eval(tokens[:i])\n",
+    "            rhs = eval(tokens[i+1:])\n",
+    "            tks = [lhs, symbol, rhs]\n",
+    "            return calc(tks)\n",
+    "            \n",
+    "    return None\n",
+    "            \n",
+    "print(parser(tokenizer('((2+3)+5)')))\n",
+    "print(parser(tokenizer('(3*(2+4))')))\n",
+    "\n",
+    "print(parser(tokenizer('((88-86)*(4/2))')))\n",
+    "        "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "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": "3.8.5"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}