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Tiny Quiz

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  • 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 Online
          R Online
          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 Online
              R Online
              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
                      • 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 Online
                        R Online
                        Rage
                        wrote on last edited by
                        #19

                        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
                        • 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
                          #20

                          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
                          • N Nicholas Marty

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

                            R Online
                            R Online
                            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
                                    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

                                      Richard DeemingR Offline
                                      Richard DeemingR Offline
                                      Richard Deeming
                                      wrote on last edited by
                                      #26

                                      :doh:


                                      "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
                                      • Richard DeemingR Richard Deeming

                                        :doh:


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

                                        R Online
                                        R Online
                                        Rage
                                        wrote on last edited by
                                        #27

                                        :laugh: good edit !

                                        ~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
                                        • N Nicholas Marty

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

                                          M Offline
                                          M Offline
                                          Mark_Wallace
                                          wrote on last edited by
                                          #28

                                          Or IDSPISPOPD (later IDCLIP), to save time. Funny how the really important things always stay in your mind.

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

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