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| 1 | +{ |
| 2 | + "cells": [ |
| 3 | + { |
| 4 | + "cell_type": "markdown", |
| 5 | + "metadata": {}, |
| 6 | + "source": [ |
| 7 | + "# **Check whether a number is prime or not by defining a function.**" |
| 8 | + ] |
| 9 | + }, |
| 10 | + { |
| 11 | + "cell_type": "markdown", |
| 12 | + "metadata": {}, |
| 13 | + "source": [ |
| 14 | + "### **METHOD 1 - Using range(2, num) (Check All Numbers Up to n-1)**" |
| 15 | + ] |
| 16 | + }, |
| 17 | + { |
| 18 | + "cell_type": "code", |
| 19 | + "execution_count": null, |
| 20 | + "metadata": {}, |
| 21 | + "outputs": [ |
| 22 | + { |
| 23 | + "name": "stdout", |
| 24 | + "output_type": "stream", |
| 25 | + "text": [ |
| 26 | + "Number 23489991 is Prime number!\n" |
| 27 | + ] |
| 28 | + } |
| 29 | + ], |
| 30 | + "source": [ |
| 31 | + "def prime_check(num):\n", |
| 32 | + " if num <= 1:\n", |
| 33 | + " print(\"1 is neither a prime nor a composite number\")\n", |
| 34 | + " else:\n", |
| 35 | + " prime = True\n", |
| 36 | + " for i in range(2, num):\n", |
| 37 | + " if num%i == 0:\n", |
| 38 | + " prime = False\n", |
| 39 | + " break\n", |
| 40 | + "\n", |
| 41 | + " if prime == True:\n", |
| 42 | + " print(f\"Number {n} is Prime number!\")\n", |
| 43 | + " else:\n", |
| 44 | + " print(f\"Number {n} is Prime number!\")\n", |
| 45 | + "\n", |
| 46 | + "\n", |
| 47 | + "n = int(input(\"Enter a no : \"))\n", |
| 48 | + "prime_check(n)" |
| 49 | + ] |
| 50 | + }, |
| 51 | + { |
| 52 | + "cell_type": "markdown", |
| 53 | + "metadata": {}, |
| 54 | + "source": [ |
| 55 | + "### **METHOD 2 - Using range(2, ceil(num/2) + 1) (Check Up to Half of the Number)**" |
| 56 | + ] |
| 57 | + }, |
| 58 | + { |
| 59 | + "cell_type": "code", |
| 60 | + "execution_count": 6, |
| 61 | + "metadata": {}, |
| 62 | + "outputs": [ |
| 63 | + { |
| 64 | + "name": "stdout", |
| 65 | + "output_type": "stream", |
| 66 | + "text": [ |
| 67 | + "Number 34578 is not prime!\n" |
| 68 | + ] |
| 69 | + } |
| 70 | + ], |
| 71 | + "source": [ |
| 72 | + "import math\n", |
| 73 | + "\n", |
| 74 | + "def prime_check(num):\n", |
| 75 | + " if num <= 1:\n", |
| 76 | + " prime = False\n", |
| 77 | + " print(\"1 is neither prime nor composite\")\n", |
| 78 | + " else:\n", |
| 79 | + " prime = True\n", |
| 80 | + " for i in range(2, math.ceil(num/2)+1):\n", |
| 81 | + " if num%i == 0:\n", |
| 82 | + " prime = False\n", |
| 83 | + " break\n", |
| 84 | + " \n", |
| 85 | + " if prime:\n", |
| 86 | + " print(f\"Number {n} is Prime!\")\n", |
| 87 | + " else:\n", |
| 88 | + " print(f\"Number {n} is not prime!\")\n", |
| 89 | + "\n", |
| 90 | + "\n", |
| 91 | + "n = int(input(\"Enter a no : \"))\n", |
| 92 | + "prime_check(n)" |
| 93 | + ] |
| 94 | + }, |
| 95 | + { |
| 96 | + "cell_type": "markdown", |
| 97 | + "metadata": {}, |
| 98 | + "source": [ |
| 99 | + "### **METHOD 3 - Using range(2, ceil(sqrt(num)) + 1) (Check Up to Square Root)**" |
| 100 | + ] |
| 101 | + }, |
| 102 | + { |
| 103 | + "cell_type": "code", |
| 104 | + "execution_count": 8, |
| 105 | + "metadata": {}, |
| 106 | + "outputs": [ |
| 107 | + { |
| 108 | + "name": "stdout", |
| 109 | + "output_type": "stream", |
| 110 | + "text": [ |
| 111 | + "Number 2347899172 is not Prime number!\n" |
| 112 | + ] |
| 113 | + } |
| 114 | + ], |
| 115 | + "source": [ |
| 116 | + "from math import sqrt, ceil\n", |
| 117 | + "\n", |
| 118 | + "def prime_checker(num):\n", |
| 119 | + " if num <= 1:\n", |
| 120 | + " prime = False\n", |
| 121 | + " print(\"1 is neither prime nor composite\")\n", |
| 122 | + " else:\n", |
| 123 | + " prime = True\n", |
| 124 | + " for i in range(2, ceil(sqrt(num)) + 1):\n", |
| 125 | + " if num%i == 0:\n", |
| 126 | + " prime = False\n", |
| 127 | + " break\n", |
| 128 | + "\n", |
| 129 | + " if prime:\n", |
| 130 | + " print(f\"Number {n} is Prime number!\")\n", |
| 131 | + " else:\n", |
| 132 | + " print(f\"Number {n} is not Prime number!\")\n", |
| 133 | + "\n", |
| 134 | + "\n", |
| 135 | + "n = int(input(\"Enter a no : \"))\n", |
| 136 | + "prime_checker(n)" |
| 137 | + ] |
| 138 | + }, |
| 139 | + { |
| 140 | + "cell_type": "markdown", |
| 141 | + "metadata": {}, |
| 142 | + "source": [ |
| 143 | + "### **METHOD 4 - Optimised approach for even numbers**" |
| 144 | + ] |
| 145 | + }, |
| 146 | + { |
| 147 | + "cell_type": "markdown", |
| 148 | + "metadata": {}, |
| 149 | + "source": [ |
| 150 | + "* Immediately handles even numbers.\n", |
| 151 | + "* Checks only odd divisors starting from 3, skipping unnecessary checks." |
| 152 | + ] |
| 153 | + }, |
| 154 | + { |
| 155 | + "cell_type": "code", |
| 156 | + "execution_count": 10, |
| 157 | + "metadata": {}, |
| 158 | + "outputs": [ |
| 159 | + { |
| 160 | + "name": "stdout", |
| 161 | + "output_type": "stream", |
| 162 | + "text": [ |
| 163 | + "Number 25127617911 is not a Prime!\n" |
| 164 | + ] |
| 165 | + } |
| 166 | + ], |
| 167 | + "source": [ |
| 168 | + "from math import ceil, sqrt\n", |
| 169 | + "\n", |
| 170 | + "def prime_check(num):\n", |
| 171 | + " if num <1:\n", |
| 172 | + " prime = False\n", |
| 173 | + " print(\"1 is neither prime nor composite!\")\n", |
| 174 | + " elif num == 2:\n", |
| 175 | + " prime = True\n", |
| 176 | + " print(f\"Number {n} is Prime!\")\n", |
| 177 | + " elif num%2 == 0:\n", |
| 178 | + " prime = False\n", |
| 179 | + " print(f\"Number {n} is not a Prime!\")\n", |
| 180 | + " else:\n", |
| 181 | + " prime = True\n", |
| 182 | + " for i in range(3, ceil(sqrt(num))+1, 2):\n", |
| 183 | + " if num%i == 0:\n", |
| 184 | + " prime = False\n", |
| 185 | + " break\n", |
| 186 | + " \n", |
| 187 | + " if prime:\n", |
| 188 | + " print(f\"Number {n} is Prime!\")\n", |
| 189 | + " else:\n", |
| 190 | + " print(f\"Number {n} is not a Prime!\")\n", |
| 191 | + "\n", |
| 192 | + "n = int(input(\"enter a number : \"))\n", |
| 193 | + "prime_check(n)" |
| 194 | + ] |
| 195 | + }, |
| 196 | + { |
| 197 | + "cell_type": "code", |
| 198 | + "execution_count": null, |
| 199 | + "metadata": {}, |
| 200 | + "outputs": [], |
| 201 | + "source": [] |
| 202 | + } |
| 203 | + ], |
| 204 | + "metadata": { |
| 205 | + "kernelspec": { |
| 206 | + "display_name": "Python 3", |
| 207 | + "language": "python", |
| 208 | + "name": "python3" |
| 209 | + }, |
| 210 | + "language_info": { |
| 211 | + "codemirror_mode": { |
| 212 | + "name": "ipython", |
| 213 | + "version": 3 |
| 214 | + }, |
| 215 | + "file_extension": ".py", |
| 216 | + "mimetype": "text/x-python", |
| 217 | + "name": "python", |
| 218 | + "nbconvert_exporter": "python", |
| 219 | + "pygments_lexer": "ipython3", |
| 220 | + "version": "3.11.0" |
| 221 | + } |
| 222 | + }, |
| 223 | + "nbformat": 4, |
| 224 | + "nbformat_minor": 2 |
| 225 | +} |
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