OpenSoure_Repos/TheAlgorithms-C-Plus-Plus
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Merge branch 'master' into circular-linked-list

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David Leal 2021-10-31 17:47:38 -06:00 committed by GitHub
commit 8e11bf7efb
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1 changed files with 17 additions and 9 deletions
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math/prime_numbers.cpp
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@ -9,14 +9,22 @@
/** Generate an increasingly large number of primes /** Generate an increasingly large number of primes
* and store in a list * and store in a list
*/ */
std::vector<int> primes(int max) { std::vector<int> primes(size_t max) {
max++;
std::vector<int> res; std::vector<int> res;
std::vector<bool> numbers(max, false); std::vector<bool> is_not_prime(max + 1, false);
for (int i = 2; i < max; i++) { for (size_t i = 2; i <= max; i++) {
if (!numbers[i]) { if (!is_not_prime[i]) {
for (int j = i; j < max; j += i) numbers[j] = true; res.emplace_back(i);
res.push_back(i); }
for (int p : res) {
size_t k = i * p;
if (k > max) {
break;
}
is_not_prime[k] = true;
if (i % p == 0) {
break;
}
} }
} }
return res; return res;
@ -25,9 +33,9 @@ std::vector<int> primes(int max) {
/** main function */ /** main function */
int main() { int main() {
std::cout << "Calculate primes up to:\n>> "; std::cout << "Calculate primes up to:\n>> ";
int n; int n = 0;
std::cin >> n; std::cin >> n;
std::vector<int> ans = primes(n); std::vector<int> ans = primes(n);
for (int i = 0; i < ans.size(); i++) std::cout << ans[i] << ' '; for (int p : ans) std::cout << p << ' ';
std::cout << std::endl; std::cout << std::endl;
} }