Check if Number is Prime

Factors are the numbers that can divide any given integer completely. Prime numbers have 2 factors only, 1 and itself. There are certain observations regarding factors.

• 1 and the digit itself will always be the factor.
• Factors always come in pairs, for example, 1*60, 2*30, 3*20, etc
• The largest factor of any digit is the digit itself.
• 2nd largest factor will be N/2, the 3rd largest factor is N/3 and the 4th largest factor is N/4, and so on.
• Factors will always be less than the square root of the number.

package org.wesome.dsalgo;

public class CheckPrime {
    public static boolean checkPrime(int prime) {
        if (prime <= 1) {
            System.out.println("1 is smallest prime number");
            return true;
        }
        for (int i = 2; i * i <= prime; i++) {
            if (prime % i == 0) {
                return false;
            }
        }
        return true;
    }
}

package org.wesome.dsalgo;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

public class CheckPrimeTest {
    @Test
    void checkPrimeTest1() {
        Assertions.assertFalse(CheckPrime.checkPrime(10));
    }

    @Test
    void checkPrimeTest2() {
        Assertions.assertTrue(CheckPrime.checkPrime(17));
    }
}

plugins {
    id 'java'
}

group = 'org.wesome'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = JavaVersion.VERSION_1_8

configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}

repositories {
    mavenCentral()
}

dependencies {
    testImplementation 'org.junit.jupiter:junit-jupiter:5.6.2'
}

test {
    useJUnitPlatform()
}