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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 18 : Pointers and Structures"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 1, Page No.: 5.130"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to print details of person using structure and pointer\n",
      "\n",
      "class account:\n",
      "    name=\"\"\n",
      "    place=\"\"\n",
      "    acctno=0\n",
      "    \n",
      "m4=account()\n",
      "m4.name=\"Venkat\"\n",
      "m4.place=\"Arcot\"\n",
      "m4.acctno=24201\n",
      "\n",
      "print \"%s\\t%s\\t%d\\n\"%(m4.name,m4.place,m4.acctno)\n",
      "\n",
      "contents=m4\n",
      "\n",
      "print \"%s\\t%s\\t%d\\n\"%(contents.name,contents.place,contents.acctno)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Venkat\tArcot\t24201\n",
        "\n",
        "Venkat\tArcot\t24201\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 2, Page No.: 5.131"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to print name, place, and account number using structure and pointer\n",
      "\n",
      "class account:\n",
      "    name=\"\"\n",
      "    place=\"\"\n",
      "    acctno=0\n",
      "    \n",
      "m4=account()\n",
      "m4.name=\"Madhavan\"\n",
      "m4.place=\"Chennai\"\n",
      "m4.acctno=241\n",
      "a=m4\n",
      "\n",
      "print \"%s\\n%s\\n%d\\n\"%(a.name,a.place,a.acctno)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Madhavan\n",
        "Chennai\n",
        "241\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example: 3, Page No.: 5.132"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to show how the int_pointers structure can be handled.\n",
      "\n",
      "\n",
      "class int_pointers:\n",
      "    p1=0\n",
      "    p2=0\n",
      "    \n",
      "pointers=int_pointers()\n",
      "m1= 80\n",
      "pointers.p1=m1\n",
      "pointers.p2=-40\n",
      "m2=pointers.p2\n",
      "print \"m1= %i, *pointers.p1 = %i\\n\"% (m1,pointers.p1)\n",
      "print \"m2= %i, *pointers.p2 = %i\\n\"% (m2,pointers.p2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "m1= 80, *pointers.p1 = 80\n",
        "\n",
        "m2= -40, *pointers.p2 = -40\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study 1: Page No.5.133"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to interchange the values stored in two variables using function with pointers. \n",
      "\n",
      "def interchange(a,b):\n",
      "    t=a\n",
      "    a=b\n",
      "    b=t\n",
      "    return b,a\n",
      "    \n",
      "a=39\n",
      "b=77\n",
      "\n",
      "print \"Before Interchange: a=%d, b=%d\"%(a,b)\n",
      "\n",
      "\n",
      "print \"After Interchange : a=%d, b=%d\"%(interchange(b,a))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Before Interchange: a=39, b=77\n",
        "After Interchange : a=77, b=39\n"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study: 2, Page No.:5.134"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to demonstrate the use of structure pointers\n",
      "\n",
      "class book:\n",
      "    bno=0\n",
      "    bname=''\n",
      "    cost=0.0\n",
      "\n",
      "p=[book()for i in range(0,3)]\n",
      "print \"Enter the Book details... \"\n",
      "print \"Enter Book number, Book Name, Book Costs... \"\n",
      "for i in range(0,3):\n",
      "    p[i].bno=input()\n",
      "    p[i].bname=raw_input()\n",
      "    p[i].cost=input()\n",
      "    \n",
      "for i in range(0,3):\n",
      "   \n",
      "    print \"\\n%d\\t%s\\t\\t%d\"%(p[i].bno,p[i].bname,p[i].cost)\n",
      "   \n",
      "print \"\\nStructure Output\\n\"\n",
      "ptr=p\n",
      "\n",
      "for i in range(0,3):\n",
      "     print \"%d\\t%s\\t\\t%d\"%(ptr[i].bno,ptr[i].bname,ptr[i].cost)\n",
      "    \n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the Book details... \n",
        "Enter Book number, Book Name, Book Costs... \n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "101\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Computer Practice_1\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "240\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "201\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Computer Practice_2\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "250\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "202\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "C++ and JAVA\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "280\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "101\tComputer Practice_1\t240\n",
        "\n",
        "201\tComputer Practice_2\t250\n",
        "\n",
        "202\tC++ and JAVA\t280\n",
        "\n",
        "Structure Output\n",
        "\n",
        "101\tComputer Practice_1\t240\n",
        "201\tComputer Practice_2\t250\n",
        "202\tC++ and JAVA\t280\n"
       ]
      }
     ],
     "prompt_number": 46
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study 3: Page No: 5.136"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to count number of vowels,consonants, digits,spaces and other characters in a line of text.\n",
      "\n",
      "vowels='aeiou'\n",
      "consonants='bcdfghjklmnpqrstvwxyz'\n",
      "spaces =' '\n",
      "digits='1234567890'\n",
      "special_characters='!@#$%^&*()_'\n",
      "\n",
      "text=raw_input(\"Enter the text in lower case: \")\n",
      "\n",
      "print \"\\nNumber of vowels: \",dict((v, text.count(v)) for v in text if v in vowels)\n",
      "print \"Number of consonants: \",dict((c, text.count(c)) for c in text if c in consonants)\n",
      "print \"Number of Spaces: \",dict((s, text.count(s)) for s in text if s in spaces)\n",
      "print \"Number of digits: \",dict((d, text.count(d)) for d in text if d in digits)\n",
      "print \"Number of special_characters: \",dict((sc, text.count(sc)) for sc in text if sc in special_characters)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the text in lower case: 123 vrb publishers @#$%^&*()\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "Number of vowels:  {'i': 1, 'e': 1, 'u': 1}\n",
        "Number of consonants:  {'b': 2, 'h': 1, 'l': 1, 'p': 1, 's': 2, 'r': 2, 'v': 1}\n",
        "Number of Spaces:  {' ': 3}\n",
        "Number of digits:  {'1': 1, '3': 1, '2': 1}\n",
        "Number of special_characters:  {'@': 1, '#': 1, '%': 1, '$': 1, '&': 1, ')': 1, '(': 1, '*': 1, '^': 1}\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study 4: Page No.: 5.136"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to demonstrate malloc() function\n",
      "\n",
      "NULL=0\n",
      "string = ''\n",
      "if string==NULL:\n",
      "    print \"Not Enough memory to allocate buffer\\n\"\n",
      "else:\n",
      "    \n",
      "    def strcpy(cstring1):\n",
      "          import copy\n",
      "          cstring2=copy.copy(cstring1)\n",
      "          return cstring2  \n",
      "string=\"Hello\"\n",
      "print \"String is %s\" %string"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "String is Hello\n"
       ]
      }
     ],
     "prompt_number": 22
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study 5: Page No.: 5.137"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to demonstrate calloc() function\n",
      "\n",
      "string=''\n",
      "\n",
      "def strcpy(cstring1):\n",
      "          import copy\n",
      "          cstring2=copy.copy(cstring1)\n",
      "          return cstring2  \n",
      "stri=\"BHAVANA\"\n",
      "string=strcpy(stri)\n",
      "print \"String is %s\" %string"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "String is BHAVANA\n"
       ]
      }
     ],
     "prompt_number": 20
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Case Study 6: Page No.:5.138"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Program to demonstrate realloc() function\n",
      "#Cannot do in python"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 29
    }
   ],
   "metadata": {}
  }
 ]
}