Friday, July 3, 2015

Project Euler 6: sums and squares (Java)

So, I've taken to trying out IntelliJ and Java for some project euler problems and then will start making small apps in there. It's been fun, these puzzles are a good way to get a quick intro into Java. There are definitely some minor differences, but for the most part navigating the IDE and not having my shortcuts be the same has been the largest challenge. There is a free 1 year subscription to IntelliJ and Resharper (for C#) if you have a student email address ending in .edu, so I recommend giving it a shot!!!

import java.util.ArrayList;
import java.util.List;

/**
 * Created by Crystal on 6/29/2015.
 */


public class Program {
    public static void main(String[] args) {
        // Project Euler #6: Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum
        // Starting value, set x to 100
        long start = System.nanoTime();

        int x = 100;

        int sumOfSquares = (x * (x + 1) * (2 * x + 1)) / 6;
        int sum = 0;
        for (int i = 1; i <= x; i++)sum += i;

        long stop = System.nanoTime();

        System.out.println(sum*sum - sumOfSquares + " is the solution calculated in a time of " + (stop - start) / 1000000 + "ms");
    }
}

25164150 is the solution calculated in a time of 0ms.