Sieve of Eratosthenes algorithm

Question

I am currently reading \"Programming: Principles and Practice Using C++\", in Chapter 4 there is an exercise in which:

I need to mak

Answer 1

Interestingly, nobody seems to have answered your question about the output problem. I don't see anything in the code that should effect the output depending on the value of max.

For what it's worth, on my Mac, I get all the output. It's wrong of course, since the algorithm isn't correct, but I do get all the output. You don't mention what platform you're running on, which might be useful if you continue to have output problems.

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Here's a version of your code, minimally modified to follow the actual Sieve algorithm.

#include 
#include 

using namespace std;

//finds prime numbers using Sieve of Eratosthenes algorithm
vector calc_primes(const int max);

int main()
{
    const int max = 100;

    vector primes = calc_primes(max);

    for(int i = 0; i < primes.size(); i++)
    {
        if(primes[i] != 0)
            cout< calc_primes(const int max)
{
    vector primes;

    // fill vector with candidates
    for(int i = 2; i < max; i++)
    {
        primes.push_back(i);
    }

    // for each value in the vector...
    for(int i = 0; i < primes.size(); i++)
    {
        //get the value
        int v = primes[i];

        if (v!=0) {
            //remove all multiples of the value
            int x = i+v;
            while(x < primes.size()) {
                primes[x]=0;
                x = x+v;
            }
        }
    }
    return primes;
}