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  4. at least he tried

at least he tried

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  • E Eric Georgiades

    as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

    if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
    {
    return true;
    }
    else
    {
    return false;
    }

    when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

    me, myself and my blog - loadx.org ericos g.

    S Offline
    S Offline
    Sylvester george
    wrote on last edited by
    #15

    He does not need any computer to find prime numbers :-D

    Regards, Sylvester G sylvester_g_m@yahoo.com

    1 Reply Last reply
    0
    • E Eric Georgiades

      as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

      if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
      {
      return true;
      }
      else
      {
      return false;
      }

      when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

      me, myself and my blog - loadx.org ericos g.

      R Offline
      R Offline
      Rage
      wrote on last edited by
      #16

      You are right, this is awful. Better is:

      int Primes[]={2,3,5,7,...,113};
      int size=sizeof(Primes[])/sizeof(Primes[0]);
      int i=0;
      while (i<size)
      {
      if (num==Primes[i]) return true;
      }
      return false;

      Last modified: 21hrs 3mins after originally posted --

      Constantly "Saving the day" should be taken as a sign of organizational dysfunction rather than individual skill - Ryan Roberts[^]

      P H B 3 Replies Last reply
      0
      • E Eric Georgiades

        as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

        if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
        {
        return true;
        }
        else
        {
        return false;
        }

        when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

        me, myself and my blog - loadx.org ericos g.

        N Offline
        N Offline
        Nemanja Trifunovic
        wrote on last edited by
        #17

        Beh, any real programmer would write it like this:

        int primes[] = {2,3,5,...133};
        const int* end = primes + sizeof(primes)/sizeof(int);
        return (std::find(primes, end, num) != end);


        Programming Blog utf8-cpp

        M P 2 Replies Last reply
        0
        • R Rage

          You are right, this is awful. Better is:

          int Primes[]={2,3,5,7,...,113};
          int size=sizeof(Primes[])/sizeof(Primes[0]);
          int i=0;
          while (i<size)
          {
          if (num==Primes[i]) return true;
          }
          return false;

          Last modified: 21hrs 3mins after originally posted --

          Constantly "Saving the day" should be taken as a sign of organizational dysfunction rather than individual skill - Ryan Roberts[^]

          P Offline
          P Offline
          PIEBALDconsult
          wrote on last edited by
          #18

          I dunno, maybe a switch statement.

          1 Reply Last reply
          0
          • R Rage

            You are right, this is awful. Better is:

            int Primes[]={2,3,5,7,...,113};
            int size=sizeof(Primes[])/sizeof(Primes[0]);
            int i=0;
            while (i<size)
            {
            if (num==Primes[i]) return true;
            }
            return false;

            Last modified: 21hrs 3mins after originally posted --

            Constantly "Saving the day" should be taken as a sign of organizational dysfunction rather than individual skill - Ryan Roberts[^]

            H Offline
            H Offline
            hlmechanic
            wrote on last edited by
            #19

            Don't you just love infinate loops?:)

            P 1 Reply Last reply
            0
            • N Nemanja Trifunovic

              Beh, any real programmer would write it like this:

              int primes[] = {2,3,5,...133};
              const int* end = primes + sizeof(primes)/sizeof(int);
              return (std::find(primes, end, num) != end);


              Programming Blog utf8-cpp

              M Offline
              M Offline
              mav northwind
              wrote on last edited by
              #20

              And any real engineer would build something like this: :D

              bool IsPrime(int i)
              {
              if (i<2)
              return false;
              if (i == 2)
              return true;
              if (i%2 == 1)
              // All odd numbers are prime:
              // 3 ... prime
              // 5 ... prime
              // 7 ... prime
              // 9 ... measuring fault
              // 11... prime
              // 13... prime
              // and so on...
              return true;
              else
              return false;
              }

              Regards, mav -- Black holes are the places where God divided by 0...

              1 Reply Last reply
              0
              • E Eric Georgiades

                as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

                if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
                {
                return true;
                }
                else
                {
                return false;
                }

                when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

                me, myself and my blog - loadx.org ericos g.

                A Offline
                A Offline
                Andre Ladeira
                wrote on last edited by
                #21

                The guy is hidden a genious! He calculated the prime numbers up to 113 without assistance! I would have stopped at 19... :-)

                S 1 Reply Last reply
                0
                • H hlmechanic

                  Don't you just love infinate loops?:)

                  P Offline
                  P Offline
                  PIEBALDconsult
                  wrote on last edited by
                  #22

                  (Pssst, I think he used a <, but didn't remember to use < when he posted.) -- modified at 20:41 Thursday 14th June, 2007

                  int Primes[]={2,3,5,7,...,113};
                  int size=sizeof(Primes[])/sizeof(Primes[0]);
                  int i=0;
                  while (i<size)
                  {
                  if (num==Primes[i]) return true;
                  }
                  return false;

                  But you're right, it lacks i++.

                  S 1 Reply Last reply
                  0
                  • P PIEBALDconsult

                    (Pssst, I think he used a <, but didn't remember to use < when he posted.) -- modified at 20:41 Thursday 14th June, 2007

                    int Primes[]={2,3,5,7,...,113};
                    int size=sizeof(Primes[])/sizeof(Primes[0]);
                    int i=0;
                    while (i<size)
                    {
                    if (num==Primes[i]) return true;
                    }
                    return false;

                    But you're right, it lacks i++.

                    S Offline
                    S Offline
                    Sylvester george
                    wrote on last edited by
                    #23

                    That is again Horror Coding :laugh:

                    Regards, Sylvester G sylvester_g_m@yahoo.com

                    L 1 Reply Last reply
                    0
                    • N Nemanja Trifunovic

                      Beh, any real programmer would write it like this:

                      int primes[] = {2,3,5,...133};
                      const int* end = primes + sizeof(primes)/sizeof(int);
                      return (std::find(primes, end, num) != end);


                      Programming Blog utf8-cpp

                      P Offline
                      P Offline
                      PIEBALDconsult
                      wrote on last edited by
                      #24

                      Ah, but in .net (C#) we can use a (generic) dictionary and an enum to further extend the required functionality...

                      public static partial class NumberKeeper
                      {
                          \[System.FlagsAttribute\]
                          public enum NumberProperty
                          {
                              None       =   0
                          ,             
                              Odd        =   1
                          ,
                              Even       =   2
                          ,
                              Positive   =   4
                          ,
                              Negative   =   8
                          ,
                              Prime      =  16
                          ,
                              PowerOfTwo =  32
                          ,
                              Square     =  64
                          ,
                              Cube       = 128
                          ,
                              Fibonacci  = 256
                          ,
                              Factorial  = 512
                      
                              /\* et cetera \*/
                          } ;
                      
                          public static readonly System.Collections.Generic.Dictionary<int,NumberProperty> Numbers ;
                      
                          static NumberKeeper
                          (
                          )
                          {
                              Numbers = new System.Collections.Generic.Dictionary<int,NumberProperty>() ;
                      
                              Numbers.Add (   0 , NumberProperty.None ) ;
                              Numbers.Add (   1 , NumberProperty.Odd  | NumberProperty.Positive                         | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci | NumberProperty.Factorial ) ;
                              Numbers.Add (   2 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Prime  | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci | NumberProperty.Factorial ) ;
                              Numbers.Add (   3 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime                              | NumberProperty.Fibonacci ) ;
                              Numbers.Add (   4 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Square | NumberProperty.PowerOfTwo ) ;
                              Numbers.Add (   5 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime                              | NumberProperty.Fibonacci ) ;
                              Numbers.Add (   6 , NumberProperty.Even | NumberProperty.Positive                                                                                | NumberProperty.Factorial ) ;
                              Numbers.Add (   7 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime  ) ;
                              Numbers.Add (   8 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Cube   | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci ) ;
                              Numbers.Add (   9 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Square ) ;
                              Numbers.Add (  10 , NumberProperty.Even | NumberProperty.
                      
                      A 1 Reply Last reply
                      0
                      • A Andre Ladeira

                        The guy is hidden a genious! He calculated the prime numbers up to 113 without assistance! I would have stopped at 19... :-)

                        S Offline
                        S Offline
                        S Douglas
                        wrote on last edited by
                        #25

                        andre-ladeira wrote:

                        He calculated the prime numbers up to 113 without assistance!

                        :cough: Unlikely ->- Pascal - Response[^] http://en.wikipedia.org/wiki/Prime_number[^]


                        1 Reply Last reply
                        0
                        • E Eric Georgiades

                          as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

                          if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
                          {
                          return true;
                          }
                          else
                          {
                          return false;
                          }

                          when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

                          me, myself and my blog - loadx.org ericos g.

                          T Offline
                          T Offline
                          ToddHileHoffer
                          wrote on last edited by
                          #26

                          I do kinda feel sorry for him. I hope you crushed his dreams of being a programmer.

                          GameFly free trial

                          1 Reply Last reply
                          0
                          • E Eric Georgiades

                            as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

                            if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
                            {
                            return true;
                            }
                            else
                            {
                            return false;
                            }

                            when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

                            me, myself and my blog - loadx.org ericos g.

                            P Offline
                            P Offline
                            Patrick Etc
                            wrote on last edited by
                            #27

                            Wow

                            1 Reply Last reply
                            0
                            • P PIEBALDconsult

                              Ah, but in .net (C#) we can use a (generic) dictionary and an enum to further extend the required functionality...

                              public static partial class NumberKeeper
                              {
                                  \[System.FlagsAttribute\]
                                  public enum NumberProperty
                                  {
                                      None       =   0
                                  ,             
                                      Odd        =   1
                                  ,
                                      Even       =   2
                                  ,
                                      Positive   =   4
                                  ,
                                      Negative   =   8
                                  ,
                                      Prime      =  16
                                  ,
                                      PowerOfTwo =  32
                                  ,
                                      Square     =  64
                                  ,
                                      Cube       = 128
                                  ,
                                      Fibonacci  = 256
                                  ,
                                      Factorial  = 512
                              
                                      /\* et cetera \*/
                                  } ;
                              
                                  public static readonly System.Collections.Generic.Dictionary<int,NumberProperty> Numbers ;
                              
                                  static NumberKeeper
                                  (
                                  )
                                  {
                                      Numbers = new System.Collections.Generic.Dictionary<int,NumberProperty>() ;
                              
                                      Numbers.Add (   0 , NumberProperty.None ) ;
                                      Numbers.Add (   1 , NumberProperty.Odd  | NumberProperty.Positive                         | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci | NumberProperty.Factorial ) ;
                                      Numbers.Add (   2 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Prime  | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci | NumberProperty.Factorial ) ;
                                      Numbers.Add (   3 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime                              | NumberProperty.Fibonacci ) ;
                                      Numbers.Add (   4 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Square | NumberProperty.PowerOfTwo ) ;
                                      Numbers.Add (   5 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime                              | NumberProperty.Fibonacci ) ;
                                      Numbers.Add (   6 , NumberProperty.Even | NumberProperty.Positive                                                                                | NumberProperty.Factorial ) ;
                                      Numbers.Add (   7 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Prime  ) ;
                                      Numbers.Add (   8 , NumberProperty.Even | NumberProperty.Positive | NumberProperty.Cube   | NumberProperty.PowerOfTwo | NumberProperty.Fibonacci ) ;
                                      Numbers.Add (   9 , NumberProperty.Odd  | NumberProperty.Positive | NumberProperty.Square ) ;
                                      Numbers.Add (  10 , NumberProperty.Even | NumberProperty.
                              
                              A Offline
                              A Offline
                              Andre Ladeira
                              wrote on last edited by
                              #28

                              Is this real c# code or just a joke? I don't know the language but it looks pretty ugly to me...

                              We're in the pipe, five by five - Terran dropship.

                              P 1 Reply Last reply
                              0
                              • P Pascal 0

                                wikipedia stops at 113 too :) http://en.wikipedia.org/wiki/Prime_number[^]

                                V Offline
                                V Offline
                                Vasudevan Deepak Kumar
                                wrote on last edited by
                                #29

                                - Pascal - wrote:

                                wikipedia stops at 113 too

                                13 is considered bad unlucky number. Is 113 fall under this category also? :-D

                                Vasudevan Deepak Kumar Personal Homepage Tech Gossips

                                1 Reply Last reply
                                0
                                • M mav northwind

                                  And, in addition to being very limited in the range of input values, the result isn't correct, either. <SmartassMode> 1 is not a prime number, by definition. </SmartassMode> ;P

                                  Regards, mav -- Black holes are the places where God divided by 0...

                                  V Offline
                                  V Offline
                                  Vasudevan Deepak Kumar
                                  wrote on last edited by
                                  #30

                                  mav.northwind wrote:

                                  1 is not a prime number, by definition.

                                  It is qualified as Unique Number right?

                                  Vasudevan Deepak Kumar Personal Homepage Tech Gossips

                                  1 Reply Last reply
                                  0
                                  • D dbrenth

                                    Should have told him he has to use this list: The first 10000 prime numbers[^]

                                    Brent

                                    V Offline
                                    V Offline
                                    Vasudevan Deepak Kumar
                                    wrote on last edited by
                                    #31

                                    dbrenth wrote:

                                    The first 10000 prime numbers[^]

                                    And any of the following things would have happened for sure: 1) Typing the if-else clause for 10000 numbers, he would broken the keyboard. 2) Typing the if-else clause for 10000 numbers, he would have broken down and ambulance should have been requested. It is an unnecessary headache, at least in this case right?

                                    Vasudevan Deepak Kumar Personal Homepage Tech Gossips

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                                    • G Giorgi Dalakishvili

                                      Ask him to write a function that returns weather or not a given number is even :D

                                      my articles

                                      V Offline
                                      V Offline
                                      Vasudevan Deepak Kumar
                                      wrote on last edited by
                                      #32

                                      Giorgi Dalakishvili wrote:

                                      Ask him to write a function that returns weather or not a given number is even

                                      And for sure, the developer would written the code which would have thrown System.StackOverFlowException :-D

                                      Vasudevan Deepak Kumar Personal Homepage Tech Gossips

                                      1 Reply Last reply
                                      0
                                      • E Eric Georgiades

                                        as an assignment, i asked for a program that we've all been through, a function that returns weather or not a given number is prime. in one case, i was given the following :

                                        if(num== 1 || num== 2 || num== 3 || num== 5 || num== 7 || num== 11 || num== 13 || num== 17 || num== 19 || num== 23 || num== 29 || num== 31 || num== 37 || num== 41 || num== 43 || num== 47 || num== 53 || num== 59 || num== 61 || num== 67 || num== 71 || num== 73 || num== 79 || num== 83 || num== 89 || num== 97 || num== 101 || num== 103 || num== 107 || num== 109 || num== 113)
                                        {
                                        return true;
                                        }
                                        else
                                        {
                                        return false;
                                        }

                                        when i asked him why he stopped at 113 (since it was the only thing i thought of asking) he said, in a tired voice, "I couldn't think of any more numbers" do you, or do you not feel sorry for him?

                                        me, myself and my blog - loadx.org ericos g.

                                        A Offline
                                        A Offline
                                        Armin Fryder
                                        wrote on last edited by
                                        #33

                                        He is a genius - always staying in business with a new update of primes!!

                                        1 Reply Last reply
                                        0
                                        • P Pascal 0

                                          wikipedia stops at 113 too :) http://en.wikipedia.org/wiki/Prime_number[^]

                                          K Offline
                                          K Offline
                                          Kevin McFarlane
                                          wrote on last edited by
                                          #34

                                          Interesting how many unproved conjectures there are.

                                          Kevin

                                          1 Reply Last reply
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