HDU 6207：Apple（Java高精度）

题目链接

题意

给出三个圆上的点，和一个目标的点，问目标点是否在这三个点构成的圆外面。

思路

许久没见过的Java高精度，不要加package！！！

import java.math.BigDecimal;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int t = scan.nextInt();
        while(t > 0) {
            t--;
            Point a = new Point(), b = new Point(), c = new Point(), tar = new Point();
            a.x = scan.nextBigDecimal();
            a.y = scan.nextBigDecimal();
            b.x = scan.nextBigDecimal();
            b.y = scan.nextBigDecimal();
            c.x = scan.nextBigDecimal();
            c.y = scan.nextBigDecimal();
            tar.x = scan.nextBigDecimal();
            tar.y = scan.nextBigDecimal();
            Point zhong = new Point();
            zhong.Waixin(a, b, c);
//            System.out.println("zhongx : " + zhong.x + ", zhongy : " + zhong.y);
//            System.out.println("tarx : " + tar.x + ", tary : " + tar.y);
            BigDecimal d1 = zhong.Cal(tar, zhong); // 目标点和圆心距离
            BigDecimal d2 = zhong.Cal(a, zhong); // 半径
//            System.out.println("d1 : " + d1 + "\n" + "d2 : " + d2);
            if(d1.compareTo(d2) != 1) System.out.println("Rejected");
            else System.out.println("Accepted");
        }
    }
}

class Point {
    public BigDecimal x;
    public BigDecimal y;

    void Waixin (Point a, Point b, Point c) {
        BigDecimal two = new BigDecimal(2);

        BigDecimal a1 = b.x.subtract(a.x), b1 = b.y.subtract(a.y); 

        BigDecimal aa1 = a1.multiply(a1);

        BigDecimal bb1 = b1.multiply(b1);

        BigDecimal cc1 = aa1.add(bb1);

        BigDecimal c1 = aa1.add(bb1);

        c1 = c1.divide(two);

        BigDecimal a2 = c.x.subtract(a.x), b2 = c.y.subtract(a.y); 

        BigDecimal aa2 = a2.multiply(a2);

        BigDecimal bb2 = b2.multiply(b2);

        BigDecimal c2 = aa2.add(bb2);

        c2 = c2.divide(two);

        BigDecimal d1 = a1.multiply(b2);

        BigDecimal d2 = a2.multiply(b1);

        BigDecimal d = d1.subtract(d2);

        BigDecimal qq = c1.multiply(b2), ww = c2.multiply(b1), ee = a1.multiply(c2), rr = a2.multiply(c1);

        BigDecimal ii = qq.subtract(ww), jj = ee.subtract(rr);

        ii = ii.divide(d);
        jj = jj.divide(d);

        this.x = a.x.add(ii);
        this.y = a.y.add(jj);
    }

    BigDecimal Cal(Point a, Point b) {
        BigDecimal xx = a.x.subtract(b.x), yy = a.y.subtract(b.y);
        xx = xx.multiply(xx);
        yy = yy.multiply(yy);
        xx = xx.add(yy);
        return xx;
    }
}