bitwise-operators

问题 Here is the original question. Here is the code for adding two integers using bitwise operations: def getSum(self, a, b): while (a & b): x = a & b y = a ^ b a = x << 1 b = y return a ^ b Though I know the reason why it goes into an infinite loop while adding a positive and negative integer, I need some help with coming up with the code-fix for this. 回答1: I am assuming that you have gone through the logic behind the infinite loop you are getting. logic Following is the behaviour of your

问题 I'm finishing up some CSE homework and I have a quick question about declaring integers of larger bit sizes. My task is to implement a function that returns 1 if any odd bit of x is 1 (assuming size of x is 32 bits) and returns 0 otherwise. Am I allowed to declare an integer with the bit value: 10101010101010101010101010101010 If so, are there any problems that could arise from this? If not, why not?? What alternatives do I have? My function: int any_odd_one(unsigned x) { int mask =

问题 I am trying to solve a question which is about writing python code for adding two integers without the use of '+' or '-' operators. I have the following code which works perfectly for two positive numbers: def getSum(self, a, b): while (a & b): x = a & b y = a ^ b a = x << 1 b = y return a ^ b This piece of code works perfectly for if input is two positive integers or two negative integers but it fails when one number is positive and other is negative. It goes into infinite loop. Any idea as

问题 I am trying to solve a question which is about writing python code for adding two integers without the use of '+' or '-' operators. I have the following code which works perfectly for two positive numbers: def getSum(self, a, b): while (a & b): x = a & b y = a ^ b a = x << 1 b = y return a ^ b This piece of code works perfectly for if input is two positive integers or two negative integers but it fails when one number is positive and other is negative. It goes into infinite loop. Any idea as

问题 Why does C#'s bitwise NOT operator return (the_number*-1)-1 ? byte a = 1; Console.WriteLine(~a); //equals -2 byte b = 9; Console.WriteLine(~b); //equals -10 // Shouldn't a=0 and b=6? How would I do this in C#? 9 = 0b1001 -> NOT = 0b0110 = 6 回答1: Bitwise operations return a value of type int (signed). Signed integers use two's-complement to represent negative numbers. Sign extension is used when going from byte to int. byte a = 1; // 0b00000001 int notA = ~a; // 0b11111110 = -128 + 64 + 32 +

问题 I need to perform a bitwise left shift on a 16-bit integer (ushort / UInt16), but the bitwise operators in C# seem to apply to int (32-bit) only. How can I use << on an ushort, or at least get to the same result with a simple workaround? 回答1: Cast the resulting value back into ushort after shifting: ushort value = 1; ushort shifted = (ushort)(value << 2); 来源： https://stackoverflow.com/questions/3819593/c-sharp-bitwise-shift-on-ushort-uint16

问题 I would like the confirmation on bitwise operators inside Android XML files. For example this line android:layout_gravity="center_horizontal|bottom" How should I read it? Are the rules inherited from Java or Android does its own interpretation of bitwise operators? Are all bitwise operators supported? If yes, could you show me the example of other operators (link is fine as well)? Thanks 回答1: The value of android_layout_gravity is parsed by Android code. As documented here, the only

问题 I noticed a SSE instruction existed for floating point AND which got me wondering. You can do the same thing with scalars in fp/integer union. The idea struck me that, if you bitwise OR the components of an array of floats, you can determine if any of them are negative quickly by looking at the sign bit of the result. What other uses exist for bitwise operations on floating point values? 回答1: A lot. For example when you only need to do bitwise operations on a floating-point only instruction

问题 I tried to understand how if condition work with bitwise operators. A way to check if a number is even or odd can be done by: #include <iostream> #include <string> using namespace std; string test() { int i = 8; //a number if(i & 1) return "odd"; else return "even"; } int main () { cout << test(); return 0; } The Part I don't understand is how the if condition work. In this case if i = 8 then the in If statement it is doing 1000 & 1 which should gives back 1000 which equal 8. If i = 7, then

问题 I have the following code : var a = parseInt('010001',2); console.log(a.toString(2)); // 10001 var b = ~a; console.log(b.toString(2)); // -10010 The MSDN Say ~ Performs the NOT operator on each bit. NOT a yields the inverted value (a.k.a. one's complement) of a. 010001 should thus return this 101110 . This Topic kinda confirm that So I can't understand how we can get -10010 instead ? The only potential explanation is that: 010001 is negated 101110 but he write this -10001 and then for an