twos-complement

问题 So I want to represent the number -12.5 . So 12.5 equals to: 001100.100 If I don't calculate the fraction then it's simple, -12 is: 110100 But what is -12.5? is it 110100.100 ? How can I calculate this negative fraction? 回答1: With decimal number systems, each number position (or column) represents (reading a number from right to left): units (which is 10^0), tens (i.e. 10^1),hundreds (i.e. 10^2), etc. With unsigned binary numbers, the base is 2, thus each position becomes (again, reading from

问题 I need to convert from two's complement to sign-magnitude in C using only the operators ! ~ & ^ | + << >> My approach is to find sign: int sign = !(!(a>>31)); basically, if sign == 1 . I want to flip the number and add 1 else just want to display the number. The thing is I can't use any loops, if statements etc. This is what I'm working on: int s_M = ((((a+1)>>31)^sign)+1)&sign; any suggestions? 回答1: From http://graphics.stanford.edu/~seander/bithacks.html#IntegerAbs int const mask = v >> 31;

问题 I need to convert from two's complement to sign-magnitude in C using only the operators ! ~ & ^ | + << >> My approach is to find sign: int sign = !(!(a>>31)); basically, if sign == 1 . I want to flip the number and add 1 else just want to display the number. The thing is I can't use any loops, if statements etc. This is what I'm working on: int s_M = ((((a+1)>>31)^sign)+1)&sign; any suggestions? 回答1: From http://graphics.stanford.edu/~seander/bithacks.html#IntegerAbs int const mask = v >> 31;

问题 I am a beginner in C . I have recently learned about 2's Complement and other ways to represent negative number and why 2's complement was the most appropriate one. What i want to ask is for example, int a = -3; unsigned int b = -3; //This is the interesting Part. Now , for the conversion of int type The standard says: 6.3.1.3 Signed and unsigned integers When a value with integer type is converted to another integer type other than _Bool, if the value can be represented by the new type, it

问题 I am looking at some c++ code and I see: byte b = someByteValue; // take twos complement byte TwosComplement = -b; Is this code taking the twos complement of b? If not, What is it doing? 回答1: This code definitely does compute the twos-complement of an 8-bit binary number, on any implementation where stdint.h defines uint8_t : #include <stdint.h> uint8_t twos_complement(uint8_t val) { return -(unsigned int)val; } That is because, if uint8_t is available, it must be an unsigned type that is

问题 Using six-bit one's and two's complement representation I am trying to solve the following problem: 12 - 7 Now, i take 12 in binary and 7 in binary first. 12 = 001100 - 6 bit 7 = 000111 - 6 bit Then, would I then flip the bit for two's complement and add one? 12 = 110011 ones complement + 1 ------- 001101 7 = 111000 ones complement + 1 --------- 111001 then, add those two complement together 001101 +111001 ------- 1000110 = overflow? discard the last digit? If so I get 5 Now, if I have a

问题 I still haven't found a reason why the lowest signed negative number doesn't have an equivalent signed positive number? I mean in a 3 digit binary number for simplicity 100 is -4? but we can't have a positive 4 in signed format because we can't. It overflows. So how do we know two's complement 1000 is -4 1000 0000 is -128 and so on? We have no original positive number 回答1: One way to think about it is that signed, two's complement format works by assigning each bit a power of two, then

问题 I need to find out that how can we represent -1 and -3 in minimum number of bits in Two's complement number system. I calculated the answer 1 and 111 but the answers seem to be incorrect. I would be very thankful if I can get some help. Thanks 回答1: Here's the formula you're probably already familiar with: N' = 2^n - N . Where n is number of bits, N' is the decimal representation of -N 's complement, and N is the cardinal number. For example, short int x = -6 is going to be N' = 2^8 - 6 = 250

问题 I have following function which counts the number of binary digits in an unsigned 32-bit integer. uint32_t L(uint32_t in) { uint32_t rc = 0; while (in) { rc++; in >>= 1; } return(rc); } Could anyone tell me please in case of signed 32-bit integer, which approach i should take ? implementing two's complement is an option. if you have any better approach, please let me know. 回答1: What about: uint32_t count_bits(int32_t in) { uint32_t unsigned_in = (uint32_t) in; uint32_t rc = 0; while (unsigned

问题 The values of a,x,y if 47x80 is the 10's complement of yaya0 is: I calculated the 10's complement of yaya0 to be 100,000-yaya0 and then. 47x80=100,000-yaya0 Now how to find values ? 回答1: 47080 + 100x = 100000 - (10000y + 1000a + 100y + 10a) 52920 = 100x + 10100y + 1010a ==> a = 2 otherwise you won`t get the 2 as tens 50900 = 100x + 10100y this can be split up in 5 = y and 9 = x + y so a = 2 x = 4 y = 5 回答2: 47x80 represents a number where 'x' is the hundreds. So does yaya0 where 'y' represent