I have reduced it for lower numbers but for some reason with higher numbers when i get the program to out put all the primes they are in minuses!!!
I need a way to make this even faster, or maybe theres a better mathematical answer, I know that for numbers in their 1,000,000,000,000 have an average of 1 prime every 26.6 numbers (i think thats right there is 37,607,912,018 primes in the number 1,000,000,000,000) is there anyway i can utilize this??
#include <iostream>
using namespace std;
int main() {
int primeanswer = 1,p = 1;
for (int i=1;i<35; i++)
What is the largest prime factor of the number 600851475143 ?
This is what I have. If I replace 600851475143 by 1000 (for example), it works fine until 2 divides 1000 to 500, 250, 125...but when it has to find the next divisible prime (ie 5) it cannot do that and the program stops working.
Code:
#include<iostream> using namespace std; bool find_prime(int number) { int factor, num; factor = 2; num = number;
Basically, I am suppose to compute 10 numbers and find their highest prime number for each of them. I've already have the inputs working, and set up 2 arrays to store inputs and their highest prime number. But I am uncertain on how to find and store their highest prime number. How to start it off?
I am currently trying to make a simple method for an array that would find the highest value. here is currently what i got, but do not know what to change to make it correct.
double FindMax(double stock[], int size){ int size = stock.length(); int max = stock[0];
for(int i = 1; i < size; i++){ if (stock[i] > max) {max = stock{i};} } return max;
5. Find the deviation of each score, and display the score and its deviation.
6. Find the Standard Deviation and Display
7. How many scores are within One Standard Deviation
So I have the average down, but I am getting stuck at the part of displaying the highest and lowest score. Every time I run the program I get two giant negative numbers for both of them. I put all the scores into a .txt file and I just opened in through the program.
I wrote some code for class to find prime numbers.The teacher says that I need to revise my code with the requirement below: use a bit array to store the prime number checking. The bit array will also be in the heap. Use the max value of an unsigned 32-bt integer (UINT_MAX) to be the maximum size of the prime number you want to check.
i want to write a program which find the biggest prime factor of a number for example the biggest prime factor of six is three or the biggest prime factor of fifteen is five. What is my program bug
Code:
#include <stdio.h> // main functions #include <math.h> // for sqrt function int main() { int i, j, k, f; // F = Flag; printf("Enter K
I had to write a program to find all the primes between 1 and 100 using the sieve of Eratosthenes so I wrote this program :
#include <iostream> #include <vector> using namespace std;
// find all the primes number using Eratosthenes int main() { vector<bool> numbers(101);
[Code] .....
My problem is that if I try to modify the program to find all the primes between 1 and max (setting the size of the vector uqual to max) my program becomes slower and I would like to listen by other people some possible solution to don't use vector in this program, the author hasn't shown me yet how to delete a value from a vector so I just used this method to solve the problem.
find the prime factors of the number input by the user. This time, we are going to have the user input a number, and the program will find all prime numbers from 2 to that number and prime factors of the number input by the user
#include <iostream> #include <cmath> using namespace std;
As an assignment for school , I've to write a program to find the sum prime factors of a user input integer.
E.g. 20 = 2 x 2 x 5 , Sum = 2 + 2 + 5 = 9 E.g. 10 = 2 x 5 , Sum = 2 + 5 = 7
My method for finding the result is as follows :
- Divide the number by increasing values if int i , starting from i=2.
- Once I get a value of i that can divide the number without giving me a remainder , I add this value of i to int sum and divide the number by i.
- I will repeat this process until the user input value is equal to 1.
My code is as shown:
#include<stdio.h> int primecheck(int n); // Function to check if i is prime int primesum(int n); // Function to sum the values of i that are prime int main(void) { int n; int sum; printf("Enter a number (> 1): "); //Prompting and scanning user input ,n scanf("%d",&n); sum = primesum(n);
[Code] .....
But for some reason I keep getting an incorrect result, it's as if it is missing out the last factor for each case.
Eg. 20 = 2 x 2 x 5 , the result I get is 4 , which is 2+2 Eg. 40 = 2 x 2 x 2 x 5 , the result I get is 6 , which is 2+2+2;
I made a program which finds the prime numbers from 0 to 100 million, and ran it on my laptop (core 2 duo, 1.83ghz, 2gb ram). It takes around 35 seconds for it to sieve all the non-prime numbers on my laptop.
I then ran the same program on a windows server, 2x 64 bit Intel Xeon Quad Core Processors @ 1.6 ghz, 6gb ram, and it takes the same amount of time, even when I set the priority to high and the affinity to all 8 cores, it seems to only use one core for the processing, is there any way to make it use all 8 cores at close to 100%?
I am trying to write code to find all the prime numbers before a user entered number. I started with a working program and when I tried to create a function, it got all messed up.
Code:
#include <stdio.h> int is_prime( int num ); int get_positive_integer(void); int main( ) { int upper; /* upper limit to check */ int num; /* current number to check */ int isprime; /* used to flag if number is prime or not */
Find all the prime numbers between a given pair of numbers. Numbers should be read in from an input file called "numbers.txt" and find all the prime numbers between them. Store the prime numbers in an array, then sort the array from greatest to least. Display the array before and after the sort.
I'm stuck on how to put the prime numbers into an array.
The input file has the numbers 1 & 100.
Here's what I have so far.
#include <iostream> #include <fstream> using namespace std; int main() { ifstream fin; fin.open("numbers.txt");
I'm a new coder for C++, and I've recently learned java before starting this programming language. I'm attempting to find all prime numbers up to the number a user enters (i.e. User enters 10, System shows "1,2,3,5,7"),
#include <iostream> #include <cstdlib> using namespace std; int main(int argc, char** argv) { int num; cout << "Enter a positive number." << endl;
[Code] ....
I've been looking at my forloop, and I can't seem to pinpoint the problem with it.
I wrote a program which sends a starting and ending range to other processes and the processes calculate the prime numbers in that range and return the count of prime numbers to the head process, process 0. But this is not working properly at the moment. I realize I still have to split up the range based on how many processes I have...I still have not figured out how I want to set that up. I
Code:
#include <stdio.h> #include <stdlib.h> #include <mpi.h> int isPrime(int num); int main(int argc, char **argv){ }
