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import java.util.Scanner;
public class Prime {
public static void main (String[] args) {
Scanner userInput = new Scanner(System.in);
int n = userInput.nextInt();
if (!(n % 2 == 0) || n == 2) {
System.out.println("not prime");
} else {
System.out.println("prime");
}
}
}
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Prime numbers: whole numbers greater than 1 that are only divisible
by 1 and itself.
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def is_prime(n):
if(n<0):
print("n is not a nature number!")
return False
for i in range(1,ceil(n/2)+1):
if (i != n and i != 1 and n%i == 0):
return False
return True
print(is_prime(int(input("number>>"))))
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a number that is divisible only by itself and 1 (e.g. 2, 3, 5, 7, 11)
suppose a number 'n' it can be divided by if '1' and only by itself then it can be a prime number
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#include <iostream>
#include <cmath>
#include <iostream>
#define el "\n"
using namespace std;
bool isprime(int n)
{
if (n <= 1)
{
return 0;
}
for(int i=2 ; i <= sqrt(n); i++) // [sqrt(n)] is faster in calculations than [n/2]
{
if(n%i == 0)
{
return 0;
}
}
return 1;
};
int main()
{
long long num;
cin >> num; // ~~~ Enter a number
(isprime(num))? cout << "The number (" << num <<") is a prime" << el : cout << "The number (" << num <<") isn't a prime" << el;
return 0;
}
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2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997
prime numbers up to 1000
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// A prime number is which cannot be divided into 2 equal parts. Any number with 2,
4,6,8 or 0 at unit place is not prime.
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number = int(input("please enter a number: "))
lis = [2, 3, 5, 7] # list of first 4 prime numbers
lis2 = [i for i in lis if number % i == 0] # if the number is prime, this list (lis 2) will be empty or that it's one of the first elements in lis which are prime numbers
if len(lis2) == 0 or number in lis:
print("Number is prime!")
else:
print("Number is NOT prime!")