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Math Puzzle

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  • D Dominik Reichl

    Umm, how many operators may I use? Because if I have an infinite number of operators, I can make an infinite long number... Btw, the number I thought of before was ((2 << 22)!) Where << is binary left shift. Now if I have an infinite number of operators, why not make (((((((((((((2 << 22)!)!)!)!)!)!)!)!)!)!)!)!) ... :confused: -Dominik


    _outp(0x64, 0xAD); and __asm mov al, 0xAD __asm out 0x64, al do the same... but what do they do?? ;)

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    Ryan Binns
    wrote on last edited by
    #13

    Aah yes, but the goal of the problem is to specify any number using three 2's and any mathematical operators, not necessarily the largest number. Say the number is n, then n = 2log2(n), but I'm not sure if this is what is wanted. Any number can be represented by either 2n or 2n+2/2, but again I'm not sure if this is what is wanted. I dunno. I'm working on it :)

    Ryan

    "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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    • R Ryan Binns

      Atlantys wrote: The largest number I can do is: 4194304 (2^22) Really?! What about 222! = approx 1.12*10426

      Ryan

      "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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      Ludvig A Norin
      wrote on last edited by
      #14

      Well then, try (2^22)! .... that ought to be quite big. Btw. the question was how to write any number, not the biggest... Part of the non-smoking generation since 12/5-2003 22.35.
      -- Opinions expressed do not neccecarily reflect those of my -- employer; I do think for myself. Resisting temptation is -- easier when you think you'll maybe get another chance -- later on.

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      • L Ludvig A Norin

        Well then, try (2^22)! .... that ought to be quite big. Btw. the question was how to write any number, not the biggest... Part of the non-smoking generation since 12/5-2003 22.35.
        -- Opinions expressed do not neccecarily reflect those of my -- employer; I do think for myself. Resisting temptation is -- easier when you think you'll maybe get another chance -- later on.

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        Ryan Binns
        wrote on last edited by
        #15

        Ludvig A. Norin wrote: Btw. the question was how to write any number, not the biggest... Yes I know. I was just surprised he couldn't get anything bigger :). See my reply to Dominik above :)

        Ryan

        "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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        • S Shree

          How can you write any positive integer using only three 2s and any mathematical operations?

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          Joaquin M Lopez Munoz
          wrote on last edited by
          #16

          0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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          • J Joaquin M Lopez Munoz

            0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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            Jorgen Sigvardsson
            wrote on last edited by
            #17

            You have a degree in mathematics, don't you? :) -- I am on fire. Do you need a light?

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            • J Joaquin M Lopez Munoz

              0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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              carrie
              wrote on last edited by
              #18

              haha, absolute genius :)

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              • J Joaquin M Lopez Munoz

                0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                Ryan Binns
                wrote on last edited by
                #19

                Well done :)

                Ryan

                "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                • J Joaquin M Lopez Munoz

                  0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                  Brad Jennings
                  wrote on last edited by
                  #20

                  Genius!:) Brad Jennings "You're mom is nice. Mind if I go out with her?" - Jörgen Sigvardsson

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                  • J Joaquin M Lopez Munoz

                    0 is simple, so is 1. For the rest: n=-log2[log2(sqrt(sqrt(...n times...(2)...))))] Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                    Shree
                    wrote on last edited by
                    #21

                    That's it!!

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                    • J Jorgen Sigvardsson

                      You have a degree in mathematics, don't you? :) -- I am on fire. Do you need a light?

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                      Joaquin M Lopez Munoz
                      wrote on last edited by
                      #22

                      No I don't :) I'm a electrical engineer, but used to be fond of these kind of quizzes when I was younger. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                      • J Joaquin M Lopez Munoz

                        No I don't :) I'm a electrical engineer, but used to be fond of these kind of quizzes when I was younger. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                        Jorgen Sigvardsson
                        wrote on last edited by
                        #23

                        Have you read Gödel Escher Bach - The Eternal Golden Braid? Your solution reminded me a lot of the authors (Hofstadter) representation of the natural numbers. He defined it by an axiom 0 (zero) and an operation S (successor). Your log/sqrt solution for simulating S gave me a flashback.. :) -- I am on fire. Do you need a light?

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                        • S Shree

                          How can you write any positive integer using only three 2s and any mathematical operations?

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                          Wesner Moise
                          wrote on last edited by
                          #24

                          The answer would involve some constructed function f(x) that increases x by 1. Then, applying f(x) to itself would allow all the positive numbers be generated. IE, f(2) = 3, and f(f(2)) = 4, and f^n(2) = 2+n-1. Since 2 is the only number we are allow, f(2) is really the only possibility, unless you want to consider f(22) or f(222) or f(2/2) or etc, but then we wastes our valuable 2s. Some functions f(x) that satisfy, are: f(x) = -(~x) --> bitwise negation followed by arithmetic negation f(x) = combination of logs and sqrts of a prior post so, my solution, the first f(x), can obtain, for example, 5 which is -~-~-~2. Thanks, Wes

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                          • S Shree

                            That's it!!

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                            Wesner Moise
                            wrote on last edited by
                            #25

                            my answer -~-~...-~2 is simpler and requires only one 2.

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                            • W Wesner Moise

                              The answer would involve some constructed function f(x) that increases x by 1. Then, applying f(x) to itself would allow all the positive numbers be generated. IE, f(2) = 3, and f(f(2)) = 4, and f^n(2) = 2+n-1. Since 2 is the only number we are allow, f(2) is really the only possibility, unless you want to consider f(22) or f(222) or f(2/2) or etc, but then we wastes our valuable 2s. Some functions f(x) that satisfy, are: f(x) = -(~x) --> bitwise negation followed by arithmetic negation f(x) = combination of logs and sqrts of a prior post so, my solution, the first f(x), can obtain, for example, 5 which is -~-~-~2. Thanks, Wes

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                              Ryan Binns
                              wrote on last edited by
                              #26

                              Brilliant! Well done :)

                              Ryan

                              "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                              • W Wesner Moise

                                The answer would involve some constructed function f(x) that increases x by 1. Then, applying f(x) to itself would allow all the positive numbers be generated. IE, f(2) = 3, and f(f(2)) = 4, and f^n(2) = 2+n-1. Since 2 is the only number we are allow, f(2) is really the only possibility, unless you want to consider f(22) or f(222) or f(2/2) or etc, but then we wastes our valuable 2s. Some functions f(x) that satisfy, are: f(x) = -(~x) --> bitwise negation followed by arithmetic negation f(x) = combination of logs and sqrts of a prior post so, my solution, the first f(x), can obtain, for example, 5 which is -~-~-~2. Thanks, Wes

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                                Shree
                                wrote on last edited by
                                #27

                                Great!!

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                                • W Wesner Moise

                                  The answer would involve some constructed function f(x) that increases x by 1. Then, applying f(x) to itself would allow all the positive numbers be generated. IE, f(2) = 3, and f(f(2)) = 4, and f^n(2) = 2+n-1. Since 2 is the only number we are allow, f(2) is really the only possibility, unless you want to consider f(22) or f(222) or f(2/2) or etc, but then we wastes our valuable 2s. Some functions f(x) that satisfy, are: f(x) = -(~x) --> bitwise negation followed by arithmetic negation f(x) = combination of logs and sqrts of a prior post so, my solution, the first f(x), can obtain, for example, 5 which is -~-~-~2. Thanks, Wes

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                                  Wesner Moise
                                  wrote on last edited by
                                  #28

                                  Regarding, my answer, -~-~-~ ... -~2, it is can be done with log n operations by appropriate using replacing some of the inner operations with the sqr or factorial functions. Thanks, Wes

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                                  • J Jorgen Sigvardsson

                                    Have you read Gödel Escher Bach - The Eternal Golden Braid? Your solution reminded me a lot of the authors (Hofstadter) representation of the natural numbers. He defined it by an axiom 0 (zero) and an operation S (successor). Your log/sqrt solution for simulating S gave me a flashback.. :) -- I am on fire. Do you need a light?

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                                    Joaquin M Lopez Munoz
                                    wrote on last edited by
                                    #29

                                    Yes, that was a nice book. If you like this sort of stuff, a lighter, but equally fun book on logic matters is What is the Name of this Book? by Raymond Smullyan. It has some Gödelian discussions in the last chapters. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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                                    • R Ryan Binns

                                      Atlantys wrote: The largest number I can do is: 4194304 (2^22) Really?! What about 222! = approx 1.12*10426

                                      Ryan

                                      "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

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                                      Atlantys
                                      wrote on last edited by
                                      #30

                                      Doh! I was trying to use an operator that causes the system to grow large very quickly. Hence ^. I complete forget about !. Dammit! I suppose that's what staying up late does to the brain. Of course... you can then do ((222!)!), etc. :~ :~ I prefer to wear gloves when using it, but that's merely a matter of personal hygiene [Roger Wright on VB] Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning. [Rich Cook]

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