欧拉工程第71题：Ordered fractions

题目链接：https://projecteuler.net/problem=71

If n<d and HCF(n,d)=1, it is called a reduced proper fraction.

n/d 真分数升序排序后，离 3/7最近的数，d<=1000000

Java程序：

public class P71{

    void run(){

        calculate();

    }

    void calculate(){

        int max_n = 1000000;

        long a = 3;

        long b = 7;

        long r = 0;

        long s = 1;

        int q = 0;

        long p = 0;

        for( q = max_n;q>2;q--){

             p = (a*q-1)/b;

            if(p*s>r*q){

                s = q;

                r = p;

            }

        }

        System.out.println(r+"/"+s);

    }

    public static void main(String[] args){

        long t0 = System.currentTimeMillis();

        new P71().run();

        long t1= System.currentTimeMillis();

        System.out.println((t1-t0)+"ms");

    }

}