C++ :: Storing Very Small Numbers - But Only Order Of Magnitude
Feb 9, 2013
I want to store a very small number - too small for even a long double. However, I don't need the number to be stored very precisely - in fact, all I really need is the order of magnitude of the number. For example, the number 5.205849034425 X 10^-381 can just be stored as an integer of -381 for my purposes. I don't really care about the precision of the 5.205849034425 part.
The reason I get this very small number, is because I am multiplying together thousands of numbers, all of which are around 0.0001 in value. So, one way to do this would be to store all these individual values as simply their order of magnitude (e.g. -4) and then instead of multiplying the numbers, I would just add up their orders of magnitude. However, I am wondering whether there is a way in C++ to do this without me having to change the way I store my data - I still would like to keep the original values if possible.
Whenever I try to call merge sort on large numbers say n=10000000. It gives an error. It works fine for small numbers, even though I have declared my Lists on the heap.
I have been writing a program to generate pairs of RSA keys using small prime numbers. I have been using mpz_invert() to get a value for d for the private key. On small prime numbers it calculates the correct value, but on larger primes it calculates incorrect values.
I'm assuming there must be an upper limit to the values the mpz_invert() function can handle? If so, what is this limit to avoid erroneous values?
i new to c++ programming. i have a program due soon in vector addition. i am to design should be able to add vectors with certain magnitude and direction and give its resultant magnitude and direction (i know how to do this mathematically but programming is not working. the user should be able to select how many vector he/she wants (i don't know how to do this, so i added 3 vectors). here's my work - i did this purely algebraically. it's still incomplete but it compiles. my "if else" statement also doesn't respond correctly.
#include <iostream> #include <string> #include <vector> #define PI 3.14159 #include <math.h> std::vector<int> v; // declares a vector of integers using namespace std;
I want it to store the integers as bits so that I am move them over and store them farther down the row as more numbers are added, but instead each new number is being added to the previous and I'm just getting a larger integer. Is this even a feasible way to store integers within an integer?
I just started learning about pointer and reference. * and &
The assignment is " Write a program that stores the following numbers in the array named miles:15,22,16,18,27,23, and 20. Have your program copy the data stored in miles to another array named dist, and then display the values in the dist array. YOur program should use pointer notation when copying and displaying array elements.
And this is what i have so far. But there is an error. I highlighted it with red. It says it's incompatible...
#include <iostream> using namespace std; const int arraynumb = 7; // declaration of keys: number of characters of keys void copyfunc(int *[], int); // function initialized int main() { int miles[arraynumb] = {15, 22, 16, 18, 27, 23, 20};
Write a program that orders three double numbers by increasing value. The program should include a function named sort3 that takes three double * arguments (pointer to double). The function prototype is void sort3(double *x, double *y, double *z); The function should reorder the values pointed to by its arguments so that after the call sort3(&x, &y, &z); the numbers satisfy . Your program should input data and print results using the following format:
Enter three numbers: 4.7 1.4 3.2 The ordered sequence is: 1.4 3.2 4.7
And here is my program: C code - 32 lines - codepad
I am getting a lot of errors when I run it through GCC. I can only use pointers.
I want to write a programm that will reverse the order of the numbers in an array (e.g. as an input 1,2,3.5,4 and as an output i want 4,3.5,2,1) . But i have to problems:
1) I do not know how to properly change the type of a numbers inside an array from int to float or double, changing int to float in front of the a[10], does not change anything instead the code does not want to compile then.
2) I also want to make an array of a number of elements typed by a user with use of a "do" loop and how to put this parameter in the code.
Here is my code:
Code:
// ConsoleApplication3.cpp : Defines the entry point for the console application.// #include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { int a[10], i, n; int pom; do { printf("number of elements in an array a: n = ");
I have to put these numbers in ascending and descending order . The interesting point of the function is that sortMe does NOT re-arrange elements in the array; instead, it uses a second array, an array of indexes for the elements in the original array and then sortMe sorts the second array based on the values in the original array. A sorted version of the original array can then be produced with these sorted indexes. I'm not sure why the function is working, even though I called it in main.
#include <iostream> #include <fstream> #include <string> using namespace std; void sortMe(int array[], int sortedIndexes[], int size, char mode); char option; const int SIZE = 5;
Write a program that prompts the user to enter three integer values, and then outputs the values in numerical sequence separated by commas.
So, if the user enters the values 10 4 6, the output should be 4, 6, 10.
If two values are the same, they should just be ordered together.
So, the input 4 5 4 should give 4, 4, 5.
Code: #include "std_lib_facilities.h" int main() { cout << "Enter three integers, separated by space: "; int a, b, c, temp1 = 0, temp2 = 0; cin >> a >> b >> c;
[Code] ....
My first solution has a bug, so here's the corrected solution, written using only features I have learned in the first three chapters:
Code: #include "std_lib_facilities.h" int main() { cout << "Enter three words, separated by space: "; string a, b, c, temp; cin >> a >> b >> c;
I have 2 arrays, one of doubles and other of integers, the doubles have the result of division of two numbers and the array with the ints have numbers that will refer to another array, but it is not important for this problem.
now using my quicksort function i will organize the array of doubles from the higher to the lower, and the ints array will follow the order of the doubles array, the result is :
Well, when i have values in the doubles array that are equal, i need to check the ints array and order the ints values, but only the ints that in the doubles array are equals, the final result will be:
What kind of code should i use for sorting numbers in both ascending and descending order? I don't know how to use bubble sorting either, is there another easy way to sort this out?
So if i write a Loop to calculate Prime Numbers in order, is there any way possible for this to happen in a shorter period of time.
The loop that i constructed took about 11hrs on a Win 7 2GB ram machine to calculate about 150,000 primes, could this be done any faster................
1. Construct a class diagram that can be used to represent food items. A type of food can be classified as basic or prepared. Basic food items can be further classified as meat, fruit, veg or Grain. The services provide by the class should be the ability to enter data for new food, to change data for food and to display existing data about food.
using this class definition write a main program to include a simple menu that offers the following choices:
1. Add food 2. Modify Food 3. Delete Food 4. Exit this menu
2. Read a list of numbers from a file and then print them out in reverse order. State whether the list is palindromic or not.
This compiles fine but when I run the .exe for the first time an error message comes up saying program has stopped working. If I run the program again without recompiling it seems to work as expected.
#include <iostream> #include<fstream> int decryption(int); int multiply(int,int[][2]); using namespace std; main(){ int n; ifstream inFile; inFile.open ("out.txt");
[Code] .....
I was trying to store numbers read from a text file into 2D array but I am getting the error above.here is where the error occurs:
I am trying to add a small function to allow me to pause the game I am making. I measure the time elapsed using the following algorithm:
1. USE ""clock_t begin=clock();"" FOR SYSTEM TIME OF GAME BEGINNING. 2. USE ""cout<<(clock()-begin)/CLOCKS_PER_SEC;"" TO DISPLAY TIME ELAPSED IN SECONDS.
Now, if I want to pause, I would want to subtract the 'paused' time from the total time elapsed.Say,
Then I would do cout<<(clock()-begin-(resume-pause))/CLOCKS_PER_SEC;
This, though is what I want, works only once(I can pause only once). I can use arrays of resume and pause, but it would still limit the number of times I can pause.
What I am looking for is a way to pause any number of times.
Suppose my file a.txt has "ABC" written in it. Now I want to write a small b before capital B in the file. How will I do it. I've tried to do it but i'm having problems.
1. When opened in app mode seekp doesn't work. 2. When opened normally previous written data is erased.
I am trying to find the best way to detect a small symbol such as :
Just for testing features I tried to load these into SURF example that comes with EMGU and it does not pick it up... And I think the technology used for SURF is better for objects with more details and color gradients...
I am having difficulty with arrays because of the limitation of the size of the arrays that I can declare. I need sizes that are very large and windows or C# does not allow me to create bigger than the following for example:
public static int[] gaPoints = new int[20000000000000000000 + 1];
I get an error message saying that "integral size is too large".
I need to be able to declare sizes that are even much larger than the abovementioned size.
