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Tiny Quiz

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  • L Lost User

    Rage wrote:

    (2-5/2)^2=(3-5/2)^2 2-5/2=3-5/2

    Cheatmode engaged.

    R Offline
    R Offline
    Rage
    wrote on last edited by
    #6

    "IDDQD"

    ~RaGE();

    I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

    M N 2 Replies Last reply
    0
    • R Rage

      -6=-6
      4-10=9-15
      4-10+25/4=9-15+25/4
      (2-5/2)^2=(3-5/2)^2
      2-5/2=3-5/2
      2=3
      2+77=3+77
      79=80

      ~RaGE();

      I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

      G Offline
      G Offline
      glennPattonWork3
      wrote on last edited by
      #7

      Hmm...(2-5/2) = -1.5, (3-5/2) = -1, therefore -1.5 != -1.0, meaning 2!=3, 79!=80 and wings stay on aeroplanes and it all falls apart, took two looks over to get it, am I right! Dang someone post it before me! Leslie mode engaged :) !

      R C 2 Replies Last reply
      0
      • G glennPattonWork3

        Hmm...(2-5/2) = -1.5, (3-5/2) = -1, therefore -1.5 != -1.0, meaning 2!=3, 79!=80 and wings stay on aeroplanes and it all falls apart, took two looks over to get it, am I right! Dang someone post it before me! Leslie mode engaged :) !

        R Offline
        R Offline
        Rage
        wrote on last edited by
        #8

        I am glad you did not really think that 79=80. ;P

        ~RaGE();

        I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

        G 1 Reply Last reply
        0
        • R Rage

          I am glad you did not really think that 79=80. ;P

          ~RaGE();

          I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

          G Offline
          G Offline
          glennPattonWork3
          wrote on last edited by
          #9

          The day I have had, a definite possibility :rolleyes:

          1 Reply Last reply
          0
          • R Rage

            "IDDQD"

            ~RaGE();

            I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

            M Offline
            M Offline
            Mark_Wallace
            wrote on last edited by
            #10

            Makes your eyes light up.

            I wanna be a eunuchs developer! Pass me a bread knife!

            1 Reply Last reply
            0
            • R Rage

              "IDDQD"

              ~RaGE();

              I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

              N Offline
              N Offline
              Nicholas Marty
              wrote on last edited by
              #11

              "IDKFA" I can't forget those codes ever, I think :laugh:

              R M 3 Replies Last reply
              0
              • N Nicholas Marty

                "IDKFA" I can't forget those codes ever, I think :laugh:

                R Offline
                R Offline
                Rage
                wrote on last edited by
                #12

                Well done. Funnily, as an AZERTY keyboard user, I know these as IDDAD and IDKFQ.

                ~RaGE();

                I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                N 1 Reply Last reply
                0
                • L Lost User

                  This

                  Random r = new Random();
                  do
                  {
                  double d = r.NextDouble();
                  double x = (d + 1) * 1070000000;
                  int y = (int)x;
                  if (y == -y)
                  break;
                  } while (true);
                  Console.WriteLine("Exit");

                  is an infinite loop. However, this

                  Random r = new Random();
                  do
                  {
                  double d = r.NextDouble();
                  double x = (d + 1) * 1080000000;
                  int y = (int)x;
                  if (y == -y)
                  break;
                  } while (true);
                  Console.WriteLine("Exit");

                  terminates with probability 1 (try it, it exits quickly in practice). Quiz: explain why OK, some people got close, but.. it's trickier than that. Take a look at the spec[^], 13.2.1:

                  o In an unchecked context, the conversion always succeeds, and proceeds as follows. • The value is rounded towards zero to the nearest integral value. If this integral value is within the range of the destination type, then this value is the result of the conversion. • Otherwise, the result of the conversion is an unspecified value of the destination type.

                  So why 0x8000000? Implementation details, but that's what it does - usually. Not always, for example:

                  Console.WriteLine(unchecked((int)1E100));

                  Prints 0. On x64, the JIT compiler uses cvttsd2si[^] which gives 0x80000000 when the value is outside the range of an int. On x86, IIRC the JIT compiler used to use fistp[^] ("the integer indefinite value" is 0x80000000) (using fistp is annoying because it requires you to change the rounding mode twice) but now it stores the double to memory and then uses cvttsd2si (at least in my tests). I'm not sure if it ever uses fisttp, but that would also give 0x80000000.

                  S Offline
                  S Offline
                  Super Lloyd
                  wrote on last edited by
                  #13

                  Simple! :-D

                  int bM = int.MaxValue, bm = int.MinValue;
                  Console.WriteLine("Min/Max: {0}/{1}, -Min/-Max: {2}/{3}", bm, bM, -bm, -bM);

                  will print

                  Min/Max: -2147483648/2147483647, -Min/-Max: -2147483648/-2147483647

                  As you can see, int.Min == -int.Min (because there is just not enough positive integer!! :laugh: ) Further, as far as int arithmetic is concerned:

                  1080000000 x2 = -2134967296

                  Morale of the story? Don't overflow! use checked() block? as in:

                  int bM = int.MaxValue, bm = int.MinValue;
                  int bm2;
                  checked
                  {
                  bm2 = -bm;
                  }

                  My programming get away... The Blog... DirectX for WinRT/C# since 2013! Taking over the world since 1371!

                  R L 2 Replies Last reply
                  0
                  • S Super Lloyd

                    Simple! :-D

                    int bM = int.MaxValue, bm = int.MinValue;
                    Console.WriteLine("Min/Max: {0}/{1}, -Min/-Max: {2}/{3}", bm, bM, -bm, -bM);

                    will print

                    Min/Max: -2147483648/2147483647, -Min/-Max: -2147483648/-2147483647

                    As you can see, int.Min == -int.Min (because there is just not enough positive integer!! :laugh: ) Further, as far as int arithmetic is concerned:

                    1080000000 x2 = -2134967296

                    Morale of the story? Don't overflow! use checked() block? as in:

                    int bM = int.MaxValue, bm = int.MinValue;
                    int bm2;
                    checked
                    {
                    bm2 = -bm;
                    }

                    My programming get away... The Blog... DirectX for WinRT/C# since 2013! Taking over the world since 1371!

                    R Offline
                    R Offline
                    Rage
                    wrote on last edited by
                    #14

                    I like Mark's answer better.

                    ~RaGE();

                    I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                    1 Reply Last reply
                    0
                    • S Super Lloyd

                      Simple! :-D

                      int bM = int.MaxValue, bm = int.MinValue;
                      Console.WriteLine("Min/Max: {0}/{1}, -Min/-Max: {2}/{3}", bm, bM, -bm, -bM);

                      will print

                      Min/Max: -2147483648/2147483647, -Min/-Max: -2147483648/-2147483647

                      As you can see, int.Min == -int.Min (because there is just not enough positive integer!! :laugh: ) Further, as far as int arithmetic is concerned:

                      1080000000 x2 = -2134967296

                      Morale of the story? Don't overflow! use checked() block? as in:

                      int bM = int.MaxValue, bm = int.MinValue;
                      int bm2;
                      checked
                      {
                      bm2 = -bm;
                      }

                      My programming get away... The Blog... DirectX for WinRT/C# since 2013! Taking over the world since 1371!

                      L Offline
                      L Offline
                      Lost User
                      wrote on last edited by
                      #15

                      It does have to do with int.MinValue, but 1080000000 * 2 = -2134967296 (in int arithmetic), and the math is done in doubles.

                      S 1 Reply Last reply
                      0
                      • L Lost User

                        It does have to do with int.MinValue, but 1080000000 * 2 = -2134967296 (in int arithmetic), and the math is done in doubles.

                        S Offline
                        S Offline
                        Super Lloyd
                        wrote on last edited by
                        #16

                        Really? is it home work and you don't understand how to code? I call that int...

                        int y = (int)x;
                        if (y == -y)

                        if you have debugging problem go to the appropriate forum... C#[^]

                        My programming get away... The Blog... DirectX for WinRT/C# since 2013! Taking over the world since 1371!

                        1 Reply Last reply
                        0
                        • R Rage

                          -6=-6
                          4-10=9-15
                          4-10+25/4=9-15+25/4
                          (2-5/2)^2=(3-5/2)^2
                          2-5/2=3-5/2
                          2=3
                          2+77=3+77
                          79=80

                          ~RaGE();

                          I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                          Richard DeemingR Offline
                          Richard DeemingR Offline
                          Richard Deeming
                          wrote on last edited by
                          #17

                          Edit: You can't expect me to do algebra this early on a Monday morning. Wait, it's the afternoon already? Well, at least it's not Tuesday yet. :-O


                          "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                          "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

                          R 1 Reply Last reply
                          0
                          • R Rage

                            Well done. Funnily, as an AZERTY keyboard user, I know these as IDDAD and IDKFQ.

                            ~RaGE();

                            I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                            N Offline
                            N Offline
                            Nicholas Marty
                            wrote on last edited by
                            #18

                            Never seen an AZERTY-Keyboard :) However nothing is as famous as ^^vv<><>ba :laugh:

                            R 1 Reply Last reply
                            0
                            • L Lost User

                              This

                              Random r = new Random();
                              do
                              {
                              double d = r.NextDouble();
                              double x = (d + 1) * 1070000000;
                              int y = (int)x;
                              if (y == -y)
                              break;
                              } while (true);
                              Console.WriteLine("Exit");

                              is an infinite loop. However, this

                              Random r = new Random();
                              do
                              {
                              double d = r.NextDouble();
                              double x = (d + 1) * 1080000000;
                              int y = (int)x;
                              if (y == -y)
                              break;
                              } while (true);
                              Console.WriteLine("Exit");

                              terminates with probability 1 (try it, it exits quickly in practice). Quiz: explain why OK, some people got close, but.. it's trickier than that. Take a look at the spec[^], 13.2.1:

                              o In an unchecked context, the conversion always succeeds, and proceeds as follows. • The value is rounded towards zero to the nearest integral value. If this integral value is within the range of the destination type, then this value is the result of the conversion. • Otherwise, the result of the conversion is an unspecified value of the destination type.

                              So why 0x8000000? Implementation details, but that's what it does - usually. Not always, for example:

                              Console.WriteLine(unchecked((int)1E100));

                              Prints 0. On x64, the JIT compiler uses cvttsd2si[^] which gives 0x80000000 when the value is outside the range of an int. On x86, IIRC the JIT compiler used to use fistp[^] ("the integer indefinite value" is 0x80000000) (using fistp is annoying because it requires you to change the rounding mode twice) but now it stores the double to memory and then uses cvttsd2si (at least in my tests). I'm not sure if it ever uses fisttp, but that would also give 0x80000000.

                              G Offline
                              G Offline
                              gardnerp
                              wrote on last edited by
                              #19

                              Because int overflows at 2147483648 and -2147483648 = 2147483648. The random number must be >= 0.98841 for the loop to break which will get hit quickly. For the first one, the random number must be > 1 which won't ever happen.

                              1 Reply Last reply
                              0
                              • Richard DeemingR Richard Deeming

                                Edit: You can't expect me to do algebra this early on a Monday morning. Wait, it's the afternoon already? Well, at least it's not Tuesday yet. :-O


                                "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                R Offline
                                R Offline
                                Rage
                                wrote on last edited by
                                #20

                                I don't know, I studied in France. Anyway, in this part of the world, (a-b)^2 = a^2 + b^2 - 2ab. If a=2 and b=5/2, (a-b)^2 = 4 + 25/4 + 2*2*5/2=4 + 25/4 + 10 If a=3 and b=5/2, (a-b)^2 = 9 + 25/4 + 2*3*5/2=4 + 25/4 + 15

                                ~RaGE();

                                I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                                C Richard DeemingR 2 Replies Last reply
                                0
                                • N Nicholas Marty

                                  Never seen an AZERTY-Keyboard :) However nothing is as famous as ^^vv<><>ba :laugh:

                                  R Offline
                                  R Offline
                                  Rage
                                  wrote on last edited by
                                  #21

                                  Here.[^] Ah, the famous Konami code[^]. Have you ever tried it here in the Lounge ? :cool:

                                  ~RaGE();

                                  I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                                  N 1 Reply Last reply
                                  0
                                  • G glennPattonWork3

                                    Hmm...(2-5/2) = -1.5, (3-5/2) = -1, therefore -1.5 != -1.0, meaning 2!=3, 79!=80 and wings stay on aeroplanes and it all falls apart, took two looks over to get it, am I right! Dang someone post it before me! Leslie mode engaged :) !

                                    C Offline
                                    C Offline
                                    Colin Mullikin
                                    wrote on last edited by
                                    #22

                                    glennPattonWork wrote:

                                    Hmm...(2-5/2) = -1.5, (3-5/2) = -1

                                    Speaking of new math, I was always under the impression that 2-5/2 = -.5 and 3-5/2 = .5 ... :doh:

                                    The United States invariably does the right thing, after having exhausted every other alternative. -Winston Churchill America is the only country that went from barbarism to decadence without civilization in between. -Oscar Wilde Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] -Colin Mullikin

                                    G 1 Reply Last reply
                                    0
                                    • R Rage

                                      Here.[^] Ah, the famous Konami code[^]. Have you ever tried it here in the Lounge ? :cool:

                                      ~RaGE();

                                      I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                                      N Offline
                                      N Offline
                                      Nicholas Marty
                                      wrote on last edited by
                                      #23

                                      Hm. Makes sense for French speaking people. Q is used quite a lot there, I guess... And yeah. There are quite few pages on the web where you can use it ;)

                                      1 Reply Last reply
                                      0
                                      • R Rage

                                        I don't know, I studied in France. Anyway, in this part of the world, (a-b)^2 = a^2 + b^2 - 2ab. If a=2 and b=5/2, (a-b)^2 = 4 + 25/4 + 2*2*5/2=4 + 25/4 + 10 If a=3 and b=5/2, (a-b)^2 = 9 + 25/4 + 2*3*5/2=4 + 25/4 + 15

                                        ~RaGE();

                                        I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus Do not feed the troll ! - Common proverb

                                        C Offline
                                        C Offline
                                        Colin Mullikin
                                        wrote on last edited by
                                        #24

                                        These Brits sure are bad at math today...

                                        Rage wrote:

                                        in this part of the world, (a-b)^2 = a^2 + b^2 - 2ab.

                                        As far as I know, that is true in all parts of the world...

                                        The United States invariably does the right thing, after having exhausted every other alternative. -Winston Churchill America is the only country that went from barbarism to decadence without civilization in between. -Oscar Wilde Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] -Colin Mullikin

                                        1 Reply Last reply
                                        0
                                        • C Colin Mullikin

                                          glennPattonWork wrote:

                                          Hmm...(2-5/2) = -1.5, (3-5/2) = -1

                                          Speaking of new math, I was always under the impression that 2-5/2 = -.5 and 3-5/2 = .5 ... :doh:

                                          The United States invariably does the right thing, after having exhausted every other alternative. -Winston Churchill America is the only country that went from barbarism to decadence without civilization in between. -Oscar Wilde Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] -Colin Mullikin

                                          G Offline
                                          G Offline
                                          glennPattonWork3
                                          wrote on last edited by
                                          #25

                                          Maff's is all mumbo jumbo! :-\

                                          1 Reply Last reply
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