integer

问题 I was working with integers in C, trying to explore more on when and how overflow happens. I noticed that when I added two positive numbers, the sum of which overflows, I always got a negative number. On the other hand, if I added two negative numbers, the sum of which overflows, I always got a positive number (including 0). I made few experiments, but I would like to know if this is true for every case. 回答1: Integer overflows are undefined behavior in C. C says an expression involving

问题 I have a question regarding how the printf() method prints integers, signed or unsigned. One day, I found myself thinking about how difficult it must be to convert a binary sequence into a sequence of decimal digits that a human can understand, given that a computer has no concept of decimal. Below, I have a printf() method (from here) with its associated methods. I've tried to understand as much as I can about how printi() works, as you can see in the comments: #define PAD_RIGHT 1 #define

问题 The following program should print whether the sum of the elements of the array is positive or negative: #include <stdio.h> #define ARR_SIZE 5 int main() { int array[ARR_SIZE] = {1,-2,3,4,-5}; unsigned sum; int i; for(i=0, sum=0; i < ARR_SIZE; i++) { sum += array[i]; printf("sum %d\n ", sum); } printf("%d\n",sum); if(sum>-1) printf("non negative\n"); else printf("negative\n"); return 0; } The program doesn't do what it is supposed to; it prints 'negative' no matter what array values it

问题 I am trying to represent a variable in the form of a string to a integer, I have done so using; atoi(str.c_str()) The string is originally obtained from a text file and stored into a; CharArrayPtr cmemblock; Which is then represented as a string; string str; for(int i = 0; i < numberofvalues; i++) { str = cmemblock[i]; int number = atoi(str.c_str()); cout << number; } If I was to change the 'cout' to print str; str = cmemblock[i]; int number = atoi(str.c_str()); cout << str; The number show

问题 I am trying to make the user inputs from the main method work on the begin method to create the size of a box in the canvas so it would create different sizes when different inputs are used This is what i have so far: import objectdraw.*; import java.awt.*; import java.util.Scanner; public class Ricochet extends WindowController { private static final int CANVAS_WIDTH=400; private static final int CANVAS_HEIGHT=600; public static void main(String [] args) { Scanner scnr = new Scanner(System

问题 I have no problem in writing this: (it also doesn't give any errors) int hex = 0xFFFFFFFF; The integer has to have an alpha value also! But when I try to do this: Integer hex = Integer.parseInt("0xFFFFFFFF"); // Or I try this: Integer hex = Integer.parseInt("FFFFFFFF"); I get a java.lang.NumberFormatException: For input string: "0xFFFFFFFF" thrown! Why is this not working? I'm guessing that there is some other way to parse hex integers that I am just not realizing, and I really need to be

问题 I would like to get an integer from mysql call as per call below, and then compare if the value is 0 or 1, I seem to have issues with the NSSTRING and NURL...please help When I set mysql with value = 1, I still don't get an utput on NSLOG NSURL *database_flag_query; NSString *database_flag; database_flag_query = [NSURL URLWithString: [NSString stringWithFormat: @"http://192.168.0.20/iqkradio_stream_ip.php"]]; database_flag = [NSString stringWithContentsOfURL:database_flag_query encoding

问题 How can we call something like this <%= habit.current_level.missed_days %> where we only call the missed_days from the current_level , instead of all the missed_days in a habit (to just give an general idea of what we want). For example if two boxes are checked, calling <%= habit.missed_days %> in the habits index will show 2 and if eight boxes are checked it will show 8 , but the goal here is that even if 8 boxes are checked: it will still only say 2 strikes in the index because we are

问题 I am currently writing a program that requires the calculation of: (x^2) mod y Both these numbers are integers. Both can be large numbers, though they never exceed 10^9. That is still enough to overflow integer for x squared. Speed is crucial for this code so gradual multiplication is not usable. Thank you. 回答1: You can take a reference from this post This should be a relatively easy example. 4^23=2^46. Now, since 2^5=32≡1(mod31), 2^46=(2^5)9×2=32^9×2≡1×2≡2(mod31) 回答2: The solution was really

问题 I need to know how to split an integer into digits in the correct order, e.g. 1234 displays as 1 2 3 4. I want it to split the integer and display the digits as words, so 1234 = 1 2 3 4 = one two three four. This is what i've got so far. It splits an integer and displays the digits as words but they are in reversed order. Sorry if its a bit messy. Also i've only just begun learning objective c so I don't know about arrays and all that stuff yet. int number, right_digit, counter; counter = 1;