Add challenge Array_strings/non_recurring_char

arrays_strings/non_repeated_char/non_repeated_char_challenge.ipynb

@@ -0,0 +1,160 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Challenge Notebook\n",
+    "\n",
+    "\n",
+    "## Problem: Implement an algorithm to find the first non-repeated character in a string\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Unit Test](#Unit-Test)\n",
+    "* [Solution Notebook](#Solution-Notebook)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume the string is ASCII\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we assume this is case sensitive\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we use additional data structures?\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we assume this fits in memory?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "* Input:- None\n",
+    "\n",
+    "    Output:- \"\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"a\"\n",
+    "\n",
+    "    Output:- \"a\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"absfasxv\"\n",
+    "\n",
+    "    Output:- \"b\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"\"\n",
+    "\n",
+    "    Output:- \"\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "Refer to the [Solution Notebook](https://github.com). If you are stuck and need a hint, the solution notebook's algorithm discussion discussion might be a good place to start."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class NonRepeatedChar(object):\n",
+    "    def non_repeated_char(self, string):\n",
+    "        # TODO: Implement me\n",
+    "        pass"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test\n",
+    "\n",
+    "**The following unit test is expected to fail until you solve the challenge.**"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# %Load test_non_repeated_char.py\n",
+    "import unittest\n",
+    "\n",
+    "class TestNonRepeatedChar(unittest.TestCase):\n",
+    "    def test_non_repeated_char(self, func):\n",
+    "        self.assertEqual(func(None), '')\n",
+    "        self.assertEqual(func('a'), 'a')\n",
+    "        self.assertEqual(func('absfasxv'), 'b')\n",
+    "        self.assertEqual(func(''), '')\n",
+    "        print('Success: test_non_repeated_char')\n",
+    "\n",
+    "def main():\n",
+    "    test = TestNonRepeatedChar()\n",
+    "    non_repeated_char = NonRepeatedChar()\n",
+    "    test.test_non_repeated_char(non_repeated_char.non_repeated_char)\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Solution Notebook\n",
+    "\n",
+    "Review the [Solution Notebook](https://github.com) for a discussion on algorithms and code solutions."
+   ]
+  }
+ ],
+ "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": "3.12.1"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

arrays_strings/non_repeated_char/non_repeated_char_solution.ipynb

@@ -0,0 +1,185 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Solution Notebook\n",
+    "\n",
+    "\n",
+    "## Problem: Implement an algorithm to find the first non-repeated character in a string\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm 1: Frequency Map](#Algorithm-1:-Frequency-Map)\n",
+    "* [Code: Frequency Map](#Code:-Frequency-Map)\n",
+    "* [Unit Test](#Unit-Test)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume the string is ASCII\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we assume this is case sensitive\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we use additional data structures?\n",
+    "    * Yes\n",
+    "\n",
+    "* Can we assume this fits in memory?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "* Input:- None\n",
+    "\n",
+    "    Output:- \"\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"a\"\n",
+    "\n",
+    "    Output:- \"a\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"absfasxv\"\n",
+    "\n",
+    "    Output:- \"b\"\n",
+    "\n",
+    "\n",
+    "* Input:- \"\"\n",
+    "\n",
+    "    Output:- \"\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Algorithm 1: Frequency Map\n",
+    "\n",
+    "A frequency map is a map which is used to denote the frequency of each element (character) in the array (string).\n",
+    "\n",
+    "We can use the frequency map to find out which characters occur only once in the string.\n",
+    "\n",
+    "Then we can check which of the characters occur sooner and output that as out answer.\n",
+    "\n",
+    "Complexity:\n",
+    "* Time: O(N log N)\n",
+    "* Space: O(N)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Code: Frequency Map"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class NonRepeatedChar(object):\n",
+    "    def non_repeated_char(self, string):\n",
+    "        if string is None or string == '':\n",
+    "            return ''\n",
+    "        \n",
+    "        # Make the frequency map\n",
+    "        frequency_map = {'a' : 0, 'b' : 0, 'c' : 0, 'd' : 0, 'e' : 0, 'f' : 0, 'g' : 0, 'h' : 0, 'i' : 0, 'j' : 0, 'k' : 0, 'l' : 0, 'm' : 0,\n",
+    "                         'n' : 0, 'o' : 0, 'p' : 0, 'q' : 0, 'r' : 0, 's' : 0, 't' : 0, 'u' : 0, 'v' : 0, 'w' : 0, 'x' : 0, 'y' : 0, 'z' : 0}\n",
+    "\n",
+    "        for char in string:\n",
+    "            frequency_map[char] += 1\n",
+    "        \n",
+    "        # Make a list of all characters with frequency of 1\n",
+    "        chars = []\n",
+    "        for char, frequency in frequency_map.items():\n",
+    "            if frequency == 1:\n",
+    "                chars.append(char)\n",
+    "        \n",
+    "        # Check which of the chars occur first and return it\n",
+    "        for char in string:\n",
+    "            if char in chars:\n",
+    "                return char\n",
+    "        \n",
+    "        # If none of the characters are non repeated then just return an empty string\n",
+    "        return ''"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Unit Test"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting test_non_repeated_char.py\n"
+     ]
+    }
+   ],
+   "source": [
+    "#%%writefile test_non_repeated_char.py\n",
+    "import unittest\n",
+    "\n",
+    "class TestNonRepeatedChar(unittest.TestCase):\n",
+    "    def test_non_repeated_char(self, func):\n",
+    "        self.assertEqual(func(None), '')\n",
+    "        self.assertEqual(func('a'), 'a')\n",
+    "        self.assertEqual(func('absfasxv'), 'b')\n",
+    "        self.assertEqual(func(''), '')\n",
+    "        print('Success: test_non_repeated_char')\n",
+    "\n",
+    "def main():\n",
+    "    test = TestNonRepeatedChar()\n",
+    "    non_repeated_char = NonRepeatedChar()\n",
+    "    test.test_non_repeated_char(non_repeated_char.non_repeated_char)\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  }
+ ],
+ "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": "3.12.1"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

arrays_strings/non_repeated_char/test_non_repeated_char.py

@@ -0,0 +1,18 @@
+import unittest
+
+class TestNonRepeatedChar(unittest.TestCase):
+    def test_non_repeated_char(self, func):
+        self.assertEqual(func(None), '')
+        self.assertEqual(func('a'), 'a')
+        self.assertEqual(func('absfasxv'), 'b')
+        self.assertEqual(func(''), '')
+        print('Success: test_non_repeated_char')
+
+def main():
+    test = TestNonRepeatedChar()
+    non_repeated_char = NonRepeatedChar()
+    test.test_non_repeated_char(non_repeated_char.non_repeated_char)
+
+
+if __name__ == '__main__':
+    main()