add pattern matching code

gaurav_pattern_matching.ipynb

@@ -0,0 +1,160 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def match(pat, text):\n",
+    "    if not pat and not text:\n",
+    "        return True\n",
+    "    if (not pat and text):\n",
+    "        return False\n",
+    "\n",
+    "    # Check if the first character is not ., *\n",
+    "    if pat[0] not in ['.', '*']:\n",
+    "        if pat[0] == text[0]:\n",
+    "            return match(pat[1:], text[1:])\n",
+    "        else:\n",
+    "            return False\n",
+    "\n",
+    "    # Check for . condition\n",
+    "    if pat[0] == '.':\n",
+    "        return match(pat[1:], text[1:])\n",
+    "\n",
+    "    # Check for * condition\n",
+    "    if pat[0] == '*':\n",
+    "        if not pat[1:]:\n",
+    "            return True\n",
+    "        else:\n",
+    "            return match(pat[1:], text) or (text and match(pat, text[1:]))  "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "code_folding": []
+   },
+   "outputs": [],
+   "source": [
+    "def tester(test_cases):\n",
+    "    for test_case in test_cases:\n",
+    "        arr, expected = test_case\n",
+    "        actual = match(arr[0],arr[1])\n",
+    "        print(\"Pattren:\\t\\t\", arr[0],\"\\nMatch String:\\t\\t\",arr[1])\n",
+    "        if actual == expected:\n",
+    "            print(\"result\\t\\t\\tSuccess!\\n\\n \")\n",
+    "        else:\n",
+    "            print(f\"\\tFailed!. Expected {expected} but got {actual}\\n\\n\") "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Pattren:\t\t a...* \n",
+      "Match String:\t\t abcdx\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t abc \n",
+      "Match String:\t\t abc\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t a* \n",
+      "Match String:\t\t abcde\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t a*b.. \n",
+      "Match String:\t\t abcg\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t a*b. \n",
+      "Match String:\t\t abc\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t a.. \n",
+      "Match String:\t\t abc\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t . \n",
+      "Match String:\t\t bc\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t . \n",
+      "Match String:\t\t b\n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n",
+      "Pattren:\t\t .* \n",
+      "Match String:\t\t \n",
+      "result\t\t\tSuccess!\n",
+      "\n",
+      " \n"
+     ]
+    }
+   ],
+   "source": [
+    "test_cases = [\n",
+    "    ((\"a...*\", \"abcdx\"),True),\n",
+    "    ((\"abc\", \"abc\"),True),\n",
+    "    ((\"a*\", \"abcde\"),True),\n",
+    "    ((\"a*b..\", \"abcg\"),True),\n",
+    "    ((\"a*b.\", \"abc\"),True),\n",
+    "    ((\"a..\", \"abc\"),True),\n",
+    "    ((\".\", \"bc\"),False),\n",
+    "    ((\".\", \"b\"),True),\n",
+    "    ((\".*\", \"\"),True),\n",
+    "]\n",
+    "tester(test_cases)"
+   ]
+  }
+ ],
+ "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": "3.6.8"
+  },
+  "toc": {
+   "base_numbering": 1,
+   "nav_menu": {},
+   "number_sections": true,
+   "sideBar": true,
+   "skip_h1_title": false,
+   "title_cell": "Table of Contents",
+   "title_sidebar": "Contents",
+   "toc_cell": false,
+   "toc_position": {},
+   "toc_section_display": true,
+   "toc_window_display": false
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}