largenumber

I'm doing some Project Euler problems and most of the time, the computations involve large numbers beyond int, float, double etc. Firstly, I know that I should be looking for more efficient ways of calculation so as to avoid the large number problem. I've heard of the Bignum libraries. But, for academics interests, I'd like to know how to code my own solution to this problem. Can any expert please help me out? (My language is C) You need to store the big numbers in a base that your computer can easily handle with its native types, and then store the digits in a variable length array. I'd

I am trying to calculate 1 + 1 * 2 + 1 * 2 * 3 + 1 * 2 * 3 * 4 + ... + 1 * 2 * ... * n where n is the user input. It works for values of n up to 12. I want to calculate the sum for n = 13 , n = 14 and n = 15 . How do I do that in C89? As I know, I can use unsigned long long int only in C99 or C11. Input 13, result 2455009817, expected 6749977113 Input 14, result 3733955097, expected 93928268313 Input 15, result 1443297817, expected 1401602636313 My code: #include <stdio.h> #include <stdlib.h> int main() { unsigned long int n; unsigned long int P = 1; int i; unsigned long int sum = 0; scanf("

I need to write an algorithm(I cannot use any 3rd party library, because this is an assignment) to divide(integer division, floating parts are not important) very large numbers like 100 - 1000 digits. I found http://en.wikipedia.org/wiki/Fourier_division algorithm but I don't know if it's the right way to go. Do you have any suggestions? 1) check divisior < dividend, otherwise it's zero (because it will be an int division) 2) start from the left 3) get equal portion of digits from the dividend 4) if it's divisor portion is still bigger, increment digits of dividend portion by 1 5) multiply

I tried to find the factorial of a large number e.g. 8785856 in a typical way using for-loop and double data type. But it is displaying infinity as the result, may be because it is exceeding its limit. So please guide me the way to find the factorial of a very large number. My code: class abc { public static void main (String[]args) { double fact=1; for(int i=1;i<=8785856;i++) { fact=fact*i; } System.out.println(fact); } } Output:- Infinity I am new to Java but have learned some concepts of IO-handling and all. public static void main(String[] args) { BigInteger fact = BigInteger.valueOf(1);

Problem: Generate large binary strings (length 2000+). Do it quickly, as this generateRandom() function will be called 300,000 times in the algorithm. Attempted Solutions: Generate 3 or 4 binary numbers and append them all together 500 times. This is awfully slow. Make a single call to random.random() and multiply it by a huge number. Convert to binary once and be done. This works for smaller numbers, but because the binary string must be a certain length, the number to convert to binary must be truly enormous (2 ** len(binString)). Current Code (works for smaller numbers):