modulus

问题 I have an NSTimeInterval that is stored as a double. I would like to get the amount of minutes that are inide of the second value using the % operator. minutes = secondValue % 60; where minutes is declared as double minutes The result is that XCode says "Invalid operands to binary %" Thoughts? 回答1: The OP changed their question, so here is my new answer: You want to do minutes = floor(secondsValue) / 60; You want int division, not modulus. 回答2: From the C standard, section 6.5.5

问题 Right now I'm using something like this: Basically the program is supposed to print X (right most digit of a #) to X decimal places for example: entered 3.56, should display 0000000000000003.560 entered 56.7 should display: 000000000056.700000 entering 1002.5 should display 00000000000001002.50 but number % 10 ,condition right now only accepts number w/o decimals, so the program closes if i enter a number with decimals I only need an alternative for number % 10 . double number; if (number %

问题 #include <stdio.h> int main() { char c; c=10; if(c%2==0) printf("Yes"); return 0; } The above code prints "Yes". Can someone tell why the modulus operator works for char and int but not for double etc.? 回答1: You already got comments explaining why % is defined for char : it's defined for all integer types, and in C, char is an integer type. Some other languages do define a distinct char type that does not support arithmetic operations, but C is not one of them. But to answer why it isn't

问题 Really been racking my brain trying to understand Modulus. This is an exercise question and the guidelines for it. here is my exercise question: Write an expression that looks for a given integer if its third digit (right to left) is 7. The guidelines say this: Divide the number by 100 and save it in a new variable, which then divide by 10 and take the remainder. The remainder of the division by 10 is the third digit of the original number. Check if it is equal to 7. So I followed the

问题 I was previously under the (naive) assumption that the modulus operator returned the remainder of division. I was apparently wrong, as -2 % 5 returns 3. I would have thought that 5 divides -2 zero times with -2 as the remainder. Now I understand the mechanics of how this operation is performed, but my question is why? Could someone give me a link to something that explains why modulus and remainder are not synonymous, or an example of a situation where it would be useful? 回答1: The result is

问题 the problem is : "Write a function to find out if a number is a prime or perfect number." so far i have worked on the perfect part first and this is what i have: #include <iostream> using namespace std; bool perfectNumber(int); int main() { int number; cout<<"Please enter number:\n"; cin>>number; bool perfectNumber(number); return 0; } bool perfectNumber(int number) { int i; int sum=0; for(i=1;i<=number/2;i++) { if(number%i==0) { sum+=i; } } if (sum==number) return i; else return 0; } HOWEVER

问题 Trying to get some code working and the modulus doesn't want to do what I want it to do... which means I have it wrong. I have unsigned char s that I'm trying to seperate out hours/minutes/seconds into so I can display them on the screen in Ascii. The variable secs is an unsigned int . Everything else is an unsigned char . I want the results in unsigned char s so not to waste memory. Working in an embedded environment. Anyone care to look at the code snippet and tell me what I've done wrong?

问题 I just heard about that x mod (2^32-1) and x / (2^32-1) would be easy, but how? to calculate the formula: x n = (x n-1 + x n-1 / b)mod b. For b = 2^32 , its easy, x%(2^32) == x & (2^32-1) ; and x / (2^32) == x >> 32 . (the ^ here is not XOR). How to do that when b = 2^32 - 1. In the page https://en.wikipedia.org/wiki/Multiply-with-carry. They say " arithmetic for modulus 2^32 − 1 requires only a simple adjustment from that for 2^32 ". So what is the "simple adjustment"? 回答1: (This answer only

问题 I want to filter for Django objects such that their "id modulo K == N" . Here's a way to do it in python, but I want it in the filter(): for foo in Foo.objects.all(): if foo.id % K == N: print foo So, I can use extra() with a query like this (please correct me if I'm wrong): Foo.objects.extra(where['id %% %s = %s' % (K,N)]) But is there a way to use F()? Django supports the use of addition, subtraction, multiplication, division and modulo arithmetic with F() objects Note: this is very wrong:

问题 I generate a pair of keys using openssl: shell> ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/Users/mike/.ssh/id_rsa): /path/to/test_rsa Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /path/to/test_rsa. Your public key has been saved in /path/to/test_rsa.pub. And then, I generate modulus from private key: shell> openssl rsa -in /path/to/test_rsa -noout -modulus > /path/to/modulus