prime number between given range in java

Wissam answered on February 13, 2022 Popularity 8/10 Helpfulness 6/10

answer prime number between given range in java

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prime number between given range in java

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/* Solution below implements the Sieve of Eratosthenes algorithm
   https://www.geeksforgeeks.org/sieve-of-eratosthenes/
   Space complexity: O(upper)
   Time complexity: O(upper*log(log(upper)))
*/

import java.util.*;
public List<Integer> primesInRange(int lower, int upper) {
	if (lower > upper || upper <= 2) {
    	return new ArrayList<>();
    }
    List<Integer> result = new ArrayList<>();
    boolean[] primes = new boolean[upper];
    for (int p = lower; p <= (int)Math.sqrt(upper); ++p) {
    	if (primes[p] == false) {
        	for (int scan = p*p; scan < upper; scan += p) {
            	primes[scan] = true;
             }
         }
    }
        
	for (int idx = lower; idx < upper; idx++) {
    	if (primes[idx] == false) {
        	result.add(idx);
         }
     }
        
	return result;
}

Popularity 8/10 Helpfulness 6/10 Language java

Source: Grepper

Tags: between java range

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Contributed on Feb 13 2022

Wissam

0 Answers Avg Quality 2/10

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prime number between given range in java

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public class PrimeExample{
    public static boolean checkPrimeNumber(int num){
        int i,m=0;
        m=num/2;
        if(num==0||num==1){
            return false; // is not prime number
        }else{
            for(i=2;i<=m;i++){
                if(num%i==0){
                    return false;  // is not prime number
                }
            }
            return true; // is prime number
        }
    }
    public static void main(String args[]){
        //to find out the prime numbers between 10 and 20, and print out the numbers.
        for(int i=10;i<=20;i++){
            if(checkPrimeNumber(i)==true){
                System.out.println(i + " is prime number");
            }
        }
    }
}

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Source: www.asenview.com

Tags: between java range

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Contributed on May 10 2022

yongpeng xu

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prime number between given range in java

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prime number between given range in java

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prime number between given range in java

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