i did a code that determine if the number is prime or not, and i have to do a one that finding the prime numbers between two variables .
the first code:
#include<iostream>
using namespace std;
int main(){
[Code].....
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");
[Code] .....
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.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <getopt.h>
#include <ctype.h>
#include <stdint.h>
//function to set all non-primes to 0
void *zero_multiples(void *threadid);
[Code] .....
I am trying to create a program that lists all prime numbers within a range of two number. Why the below program isn't working?
#include <iostream>
using namespace std;
int main(){
int high_range;
int low_range;
int w;
[Code] .....
#include<iostream>
#include <cstdlib>
using namespace std;
[Code].....
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.
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 */
[Code]...
It says the error is on line 23
The code below is suppose to output all the prime numbers between the values of startNum and endNum variables. but its not working correctly instead it display all the numbers between startnum and endNumber including non-prime numbers.
void PrimeFinder::run(){
bool isPrime = false;
for(int i = startNum; i <= endNum; i++) {
for(int j = 2; j < i; j++){
if((i % j) == 0)
[Code] ....
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){
}
[code]....
I have a program that gets prime numbers that doesn't work. It looks like it works for all prime numbers except odd non-prime ones. Here is the code:
Code:
#include <iostream>
using namespace std;
bool isPrime(int prime) {
while(true) {
int track = 0;
[Code] ...
I seem to have reached a dead end in a program I am attempting to write.The purpose of the program is find the smallest, largest, and average values in a collection of N numbers. It needs to get the value of N before scanning each value in the collection of N numbers.I'm having trouble creating comparisons for each set. I have a feeling because of the way I structured my program, I'm unable to make a proper comparison. Maybe my approach was wrong as soon as I got to the for statement to loop N sets and N numbers.Here is my code so far:
Code:
#include <stdio.h>
int main (void)
{
int num_sets, num_of_integers;
int count, count2, set, sum = 0;
int num, avg;
}
[code]....
/* Here is where I would continue to attempt to make a comparison between sets to determine smallest to largest */
return 0;
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 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++)
[Code] .....
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
[Code]...
While finding the primes , I do not know how to make it into one array so that...
View 7 Replies View RelatedI wrote this program to print prime numbers between 2 and 10 but it only prints '3'. here is the code
#include<iostream>
#include<conio.h>
using namespace std;
int prime(int x, int y);
void main(){
int n=2;
[code].....
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;
[Code]......
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've looked through my code numerous times.
Code:
#include<stdio.h>
int main(){
int num,i,count,min,max,sum=0;
printf("Enter min range: ");
scanf("%d",&min);
[code]....
when I ran the program , I got "4" with prime numbers. I only way I was able to remove the "4" was this "num!=4".
I was going through a book I have about C trying to learn about arrays, and one of the first few examples of what could been done with an array was showing how to use an array to generate a list of prime numbers. I've been staring at this program for about an hour trying to understand how it works (it does), but the workings of one for loop within the program.
Code:
#include <stdio.h>
#include <stdbool.h>
int main () {
int p, i, primes[50], primeIndex = 2;
bool isPrime;
[Code]...
So that is saying in order for this loop to go on, really two conditions must be met since there's that && operator. isPrime must be true (I think that's what it means by just having "isPrime" and not setting it equal to anything) and p / primes[i] must be greater than or equal to primes[i].So at the beginning of the loop, since i = 1, p = 5 (as per surrounding loop), and prime[i] = 3 ( as per the variable assignment at the beginning of the program ), the loop condition would be "isPrime && 5 / 3 >= 3"
"5 / 3 >= 3" The loop should stop right there! 1.666666667 is NOT greater than or equal to 3!
Code:
#include <stdio.h>
int find_next_prime(int num);
int is_prime(int num);
int main()
[Code]......
How would I go about counting the number of times a factorial has a specific prime number?
For example, 5! = (2^3)*(3^1)*(5^1), 6! = (2^4)*(3^2)*(5^1).
How would I begin to design my find_prime_count function in order to count how many times each occurs? My program is to read in a number between (2<=N<=100) from a text file and output the results exactly like above which I still have to figure out after, I'll assume I have to use fscanf.
I have an assignment where I have to use two for loops. I need to ask the user for any two numbers and be able to list all the numbers in between and their factors and state whether or not the number is prime or not.
View 2 Replies View RelatedWrite a c++ program to print out the first n prime numbers and the sum of the first n prime numbers.
View 7 Replies View RelatedI keep getting this error:
||In function 'int main()':|
|19|error: too few arguments to function 'int isPrime(int, int)'|
|13|note: declared here|
Code:
#include <iostream>
#include <fstream>
using namespace std;
int isPrime(int , int);
int main() {
int result = 0;
[Code] ....
The object is to have the user enter in the number of days then the day the calendar would start on. This part I was able to achieve and run okay. Once I wanted to get the values/days that were prime to have a P besides them this is where I ran into trouble. In this case P stands for prime numbers.
The issue I have is that some of the values that are prime have the correct P but others have the P as well such as 9, 15, and 25 - which are not prime numbers.
I was able to create a program that checked for prime numbers separately but I had issues merging them. Below is the merged code followed by the prime checker.
#include <stdio.h>
int main(int argc, const char * argv[]) {
int i, N, Start;
int j, GetNumber, PrimeNumber = 0;
[code].....