Checker numeru pierwszego
/*
C++ Prime Number Checker program by lolman_ks.
This logic can be used to build this program in other languages also.
*/
/*
Logic: Divide the number by all numbers less than half of the number to
check. If it is divisible by any of them, return False.
*/
#include <iostream>
#include <cmath>
using namespace std;
bool isPrime(int number){
if(number == 1) return false; //1 is neither prime nor composite.
else if(number < 1) return false;
/*
O is the 0th multiple of every number, x * 0 = 0. Therefore 0 is not
prime.
Any -ve number is also composite because it has at least 3 factors:
Itself, 1 and -1.
*/
else if(number == 2) return true; //Only even prime number;
else{
for(int i = 0;i <= ceil(number / 2);++i){
if(number % i == 0) return false; //Check exact divisibility.
}
return true;
/*
Return true if the loop is not broken and the number is not exactly
divisible by any number.
*/
}
}
//Implementations of this function.\
//Check prime numbers upto a limit.
int main(){
int limit;
cout << "Enter limit: ";cin >> limit;
for(int i = 0;i <= limit;++i){
cout << i << ": " << isPrime(i) << endl;
}
}
/*
I hope my answers are useful to you, please promote them if they are.
#lolman_ks.
*/
LOLMAN_KS