The Big Programming Thread - Page 176

   for (int i = b; i <= a; i++)
   {
      for (int j = 2; j <= sqrt(i); j++)
      {
         if (i%j != 0 && i%2 != 0)
         {
            cout << i << " is prime" << endl;
         }
      }
   }

int is_prime(unsigned number) {
    ... is the number prime?
}

for /* number in low to high */ {
    if (is_prime(number)) {
        ...
    }
}

private static boolean isPrime(final int x){
    if( y < 2 )
        return false;
    if( y == 2 )
        return true;
    if( y % 2 == 0 )
        return false;
    int t = sqrt(x);
    for(int i = 3; i < t; i+=2 ) // you don't need to worry about other evens
        if( x % i == 0 )
            return false;
    return true;
}

age = age++;

age = age + 1;

age++;

public Automobile(int model, String manufacturer) {
    this.model = model;
    this.manufacturer = manufacturer;
}

#include <vector>
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <ctime>
#include <chrono>
#include <ppl.h>
#include <concurrent_vector.h>
int main()
{
    std::chrono::time_point<std::chrono::system_clock> TimeStart;
std::chrono::time_point<std::chrono::system_clock> TimeEnd;

	concurrency::concurrent_vector<int> primes;
	primes.push_back(2);

	TimeStart = std::chrono::system_clock::now();

	int Start = 3;
	int Stop = 4000000;
	int Step = 2;

	// Comment out the multi-threaded version and uncomment the single threaded version to see the difference
	/// Multi-Threaded version
	Concurrency::parallel_for(Start,Stop, Step, [&primes](int n)
	{
		auto prime = true;
		int stop = sqrt(n);

		for(auto j=2;j<stop;j++)
		{
			if(n%j==0)
			{
				prime = false;
				break;
			}
		}
	
		if(prime)
			primes.push_back(n);
	});

	TimeEnd = std::chrono::system_clock::now();
	auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(TimeEnd-TimeStart).count();
	auto seconds = std::chrono::duration_cast<std::chrono::seconds>(TimeEnd-TimeStart).count();
	std::cout << "Milliseconds : "<< millis << std::endl;
	std::cout << "Seconds      : "<< seconds << std::endl;
	return 0;
}

public Automobile(int modelYear, String manufacturer, Driver driver) {
    this.modelYear = modelYear;
    this.manufacturer = manufacturer;
    this.driver = driver;
}

int calculateInsurance(){
    int extra = 0;
    if ( this.getModelYear < 2002 ) extra += 50;
    if ( this.driver.getAge() < 25 ) extra += 200;
    return 900 + extra;
}

      for (int i = lower limit; i <= upper limit; i++)    //user inputs two numbers and looks for prime numbers between the two
      {
         for (int j = 2; j <= sqrt(i); j++)
         {
            if (i%j == 0 && i%2 == 0)
            {
               cout << i + 1 << " is prime" << endl;
            }
         }
      }

      for (int i = lower limit; i <= upper limit; i++)    //user inputs two numbers and looks for prime numbers between the two
      {
         for (int j = 2; j <= sqrt(i); j++)
         {
            if (i%j == 0 && i%2 == 0)
            {
               cout << i + 1 << " is prime" << endl;
            }
         }
      }

for (int j = 2; j <= sqrt(5); j++) {
    if (5 % j == 0 && 5 % 2 == 0) {
        ... 6 is prime
    }
}