TheAlgorithms-C-Plus-Plus/math/prime_numbers.cpp
2020-05-27 16:45:33 -04:00

34 lines
787 B
C++

/**
* @file
* @brief Get list of prime numbers
* @see primes_up_to_billion.cpp sieve_of_eratosthenes.cpp
*/
#include <iostream>
#include <vector>
/** Generate an increasingly large number of primes
* and store in a list
*/
std::vector<int> primes(int max) {
max++;
std::vector<int> res;
std::vector<bool> numbers(max, false);
for (int i = 2; i < max; i++) {
if (!numbers[i]) {
for (int j = i; j < max; j += i) numbers[j] = true;
res.push_back(i);
}
}
return res;
}
/** main function */
int main() {
std::cout << "Calculate primes up to:\n>> ";
int n;
std::cin >> n;
std::vector<int> ans = primes(n);
for (int i = 0; i < ans.size(); i++) std::cout << ans[i] << ' ';
std::cout << std::endl;
}