initial code commit

dont you dare criticise my code uwu
just some boredom project where i tried to make a prime number finder algorithm that is as efficient as possible

algorithm-uwu.cpp

@@ -0,0 +1,114 @@
+// primes.cpp : This file contains the 'main' function. Program execution begins and ends there.
+//
+
+#include <iostream>
+#include <cmath>
+#include <string>
+#include <vector>
+
+#include <chrono>
+
+using namespace std;
+using namespace std::chrono;
+
+//unsigned long long origI = 3;
+//unsigned long long n = 100000000;
+unsigned int origI = 3;
+unsigned int n = 100000;
+vector<unsigned int> vprimes {2};
+
+milliseconds ms1 = duration_cast<milliseconds>(
+	system_clock::now().time_since_epoch()
+);
+
+int main()
+{
+	/*
+	unsigned int count = 0;
+	bool isprime;
+	for (auto i=origI; i <= n; ++i) {
+		//if ((int)pow(2, (i - 1)) % i != 1) continue;
+		isprime = true;
+		if (i % 2 == 0) isprime = false;
+		for (int o = 3; o <= sqrt(i); o+=2) {
+			if (i % o == 0) isprime = false;
+		}
+		if (isprime) {
+			//cout << i << endl;
+			++count;
+		}
+	}
+	*/
+
+	unsigned int count = 0;
+	bool isprime;
+
+	for (auto i = 3; i <= sqrt(n); ++i) {
+		//if ((int)pow(2, (i - 1)) % i != 1) continue;
+		isprime = true;
+		if (i % 2 == 0) { isprime = false; continue; };
+
+
+		for (auto p : vprimes) {
+			if (p <= sqrt(i)) {
+				if (i % p == 0) isprime = false;
+			}
+			else {
+				break;
+			}
+		}
+		if (isprime) {
+			//cout << i << " added to fix" << endl;
+			vprimes.push_back(i);
+		}
+	}
+
+	for (auto i = origI; i <= n; ++i) {
+		//if ((int)pow(2, (i - 1)) % i != 1) continue;
+		isprime = true;
+		if (i % 2 == 0) { isprime = false;continue; };
+
+
+		for (auto p : vprimes) {
+			if (p <= sqrt(i)) {
+				if (i % p == 0) {
+					isprime = false;
+					break;
+				}
+			}
+			else {
+				break;
+			}
+		}
+		if (isprime) {
+			//cout << i << endl;
+			++count;
+			vprimes.push_back(i);
+		}
+	}
+	
+	
+	
+
+	milliseconds ms2 = duration_cast<milliseconds>(
+		system_clock::now().time_since_epoch()
+	);
+
+	//cout << endl << endl << "There are " << count << " prime numbers between " << origI << " and " << n << endl << "The whole operation took about " << (long)ms2.count() - (long)ms1.count() << "ms to complete";
+	cout << endl << endl << "There are " << count << " prime numbers between " << origI << " and " << n << endl << "The whole operation took about " << (long)ms2.count() - (long)ms1.count() << "ms to complete";
+	
+	
+	/*
+
+	vector:
+		3 - 1'000'000 : 12784ms
+		3 - 2'000'000 : 25227ms
+		3 - 5'000'000 : 58557ms
+	
+	just loops:
+		3 - 1'000'000 : 15135ms
+		3 - 2'000'000 : 32723ms
+		3 - 5'000'000 : 84439ms
+
+	*/
+}