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GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
trønderen19-Sep-20 7:06
Membertrønderen19-Sep-20 7:06 
GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
Richard MacCutchan19-Sep-20 21:05
mveRichard MacCutchan19-Sep-20 21:05 
AnswerRe: How can I calculate time complexity and compare between given two algorithms? Pin
Sandeep Mewara19-Sep-20 0:12
mveSandeep Mewara19-Sep-20 0:12 
GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
Member 1151248619-Sep-20 0:55
MemberMember 1151248619-Sep-20 0:55 
GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
Gerry Schmitz19-Sep-20 3:00
mveGerry Schmitz19-Sep-20 3:00 
GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
trønderen19-Sep-20 7:03
Membertrønderen19-Sep-20 7:03 
GeneralRe: How can I calculate time complexity and compare between given two algorithms? Pin
Gerry Schmitz20-Sep-20 4:52
mveGerry Schmitz20-Sep-20 4:52 
QuestionMy implementation of Eratosthenes sieve is horribly slow. But why? Pin
Member 149328737-Sep-20 22:00
MemberMember 149328737-Sep-20 22:00 
Hi all, i tried to implement the Sieve of Eratosthenes for finding all primes under a given number n.

I came up with the this solution, and i think its kind of neat. But when i run it, it is many times slower than the standard solution i found on the net afterwards.

Can someone explain to me, why my solution is slower:

public static List<Integer> sieveEratosthenes(List<Integer> numbers){

    int baseNum = 0;

    while(baseNum < Math.sqrt(numbers.size())){

        for(int i = 1; i < numbers.size()-baseNum; i++){

            if(numbers.get(baseNum+i) % numbers.get(baseNum) == 0)
            {
                numbers.remove(baseNum+i);
            }
        }
        baseNum++;
    }

    System.out.println("Calcs: "+calc);
    return numbers;
}

AnswerRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Richard MacCutchan7-Sep-20 22:38
mveRichard MacCutchan7-Sep-20 22:38 
GeneralRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Richard Deeming7-Sep-20 23:59
mveRichard Deeming7-Sep-20 23:59 
AnswerRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Dave Kreskowiak8-Sep-20 6:46
mveDave Kreskowiak8-Sep-20 6:46 
GeneralRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Richard Andrew x6422-Sep-20 10:36
professionalRichard Andrew x6422-Sep-20 10:36 
GeneralRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Dave Kreskowiak22-Sep-20 16:25
mveDave Kreskowiak22-Sep-20 16:25 
AnswerRe: My implementation of Eratosthenes sieve is horribly slow. But why? Pin
Patrice T18-Sep-20 19:51
mvePatrice T18-Sep-20 19:51 
QuestionHow can I remove alternate words from a sentence? Pin
maicart5-Sep-20 22:27
Membermaicart5-Sep-20 22:27 
AnswerRe: How can I remove alternate words from a sentence? Pin
Gerry Schmitz6-Sep-20 4:14
mveGerry Schmitz6-Sep-20 4:14 
GeneralRe: How can I remove alternate words from a sentence? Pin
Richard MacCutchan6-Sep-20 6:13
mveRichard MacCutchan6-Sep-20 6:13 
GeneralRe: How can I remove alternate words from a sentence? Pin
Gerry Schmitz6-Sep-20 6:33
mveGerry Schmitz6-Sep-20 6:33 
AnswerRe: How can I remove alternate words from a sentence? Pin
Richard MacCutchan6-Sep-20 4:52
mveRichard MacCutchan6-Sep-20 4:52 
GeneralRe: How can I remove alternate words from a sentence? Pin
maicart6-Sep-20 6:23
Membermaicart6-Sep-20 6:23 
GeneralRe: How can I remove alternate words from a sentence? Pin
Richard MacCutchan6-Sep-20 6:41
mveRichard MacCutchan6-Sep-20 6:41 
GeneralRe: How can I remove alternate words from a sentence? Pin
Richard Andrew x646-Sep-20 8:04
professionalRichard Andrew x646-Sep-20 8:04 
GeneralRe: How can I remove alternate words from a sentence? Pin
maicart7-Sep-20 1:27
Membermaicart7-Sep-20 1:27 
GeneralRe: How can I remove alternate words from a sentence? Pin
Richard MacCutchan7-Sep-20 1:38
mveRichard MacCutchan7-Sep-20 1:38 
Questionalgorithm to place N rectilinear blocks in a ring to minimize total area Pin
rbuchana14-Aug-20 5:21
Memberrbuchana14-Aug-20 5:21 

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