logic

I'd like to get the sign of a float value as an int value of -1 or 1. Avoiding conditionals is always a good idea in reducing computational cost. For instance, one way I can think of would be to use a fast bit-shift to get the sign: float a = ...; int sign = a >> 31; //0 for pos, 1 for neg sign = ~sign; //1 for pos, 0 for neg sign = sign << 1; //2 for pos, 0 for neg sign -= 1; //-1 for pos, 1 for neg -- perfect. Or more concisely: int sign = (~(a >> 31) << 1) - 1; Does this seem like a good approach? Will this work for all platforms, given endianness concerns (as MSB holds sign)? assylias Any

I have to create a function bitParity(int x) that takes an integer and returns 1 if there is an odd number of 0 's in the bit form of x , and 0 otherwise. Ex: bitParity(5) = 0, bitParity(7) = 1 However, this is difficult as I can only use bit operators on this problem ( ! ˜ & ˆ | + << >> are the only legal ones). That means, no loops, if-then , or anything of the sort. Constants can be used. So far, what I have doesn't work, but I figured that I should shift the bits of the integer 16 , 8 , and 4 times and XOR the remaining integers. Can anyone offer some advice? Thanks. This is properly

I'm new but have managed to learn a lot and create a pretty awesome (I hope) app that's near completion. One of my last tasks is to create a PDF of dynamically generated user data. It has been the most frustrating part of this whole process as there is no real modern clear cut template or guide. Apple's documentation isn't very descriptive (and some parts I don't understand) and the Q/A here on stack and examples on Google all seem very case specific. I thought I almost had it by using a UIScrollView but the end result was messy and I couldn't get things to line up neat enough, nor did I have

I want to know the process which usually web apps follow to maintain login between multiple requests and also how they manage things using COOKIES. In my login form I am providing "Remember Me" feature. When user login then I check the username and password validity from database. If its valid then I check if "Remember me" is selected, if yes then storing username and password in session, encrypted format. And finally storing username and password in SESSION. When user navigates form one page to another, first I run login check script which checks if there is any value in cookies, then it

i have to reverse the position of integer like this input = 12345 output = 54321 i made this but it gives wrong output e.g 5432 #include <iostream> using namespace std; int main(){ int num,i=10; cin>>num; do{ cout<< (num%i)/ (i/10); i *=10; }while(num/i!=0); return 0; } Your loop terminates too early. Change }while(num/i!=0); to }while((num*10)/i!=0); to get one more iteration, and your code will work. Here is a solution int num = 12345; int new_num = 0; while(num > 0) { new_num = new_num*10 + (num % 10); num = num/10; } cout << new_num << endl; If you try it once as an example, you'll see

This question is more related to logic than any programming language. If the question is not apt for the forum please do let me know and I will delete this. I have to write a logic to calculate scores for blogs for a Blog Award website. A blog may be nominated for multiple award categories and is peer-reviewed or rated by a Jury on a -1 to 5 scale (-1 to indicate a blog they utterly dislike). Now, a blog can be rated by one or more Jurors. One criterion while calculating final score for a blog is that if a blog is rated positively by more people it should get more weightage (and vice-versa).