poj 6206 Apple _Apple

【poj 6206 Apple】黄沙百战穿金甲，不破楼兰终不还。这篇文章主要讲述poj 6206 Apple相关的知识，希望能为你提供帮助。
AppleTime Limit: 1000/1000 MS (java/Others) Memory Limit: 65535/32768 K (Java/Others)
Total Submission(s): 806 Accepted Submission(s): 267

Problem Description Apple is Taotao‘s favourite fruit. In his backyard, there are three apple trees with coordinates (x1,y1), (x2,y2), and (x3,y3). Now Taotao is planning to plant a new one, but he is not willing to take these trees too close. He believes that the new apple tree should be outside the circle which the three apple trees that already exist is on. Taotao picked a potential position (x,y) of the new tree. Could you tell him if it is outside the circle or not?
Input The first line contains an integer T, indicating that there are T(T≤30) cases.
In the first line of each case, there are eight integers x1,y1,x2,y2,x3,y3,x,y, as described above.
The absolute values of integers in input are less than or equal to 1,000,000,000,000.
It is guaranteed that, any three of the four positions do not lie on a straight line.
Output For each case, output "Accepted" if the position is outside the circle, or "Rejected" if the position is on or inside the circle.
Sample Input

3 -2 0 0 -2 2 0 2 -2 -2 0 0 -2 2 0 0 2 -2 0 0 -2 2 0 1 1

Sample Output

Accepted Rejected Rejected

只需要输入三个点的坐标即可 p1(x1,y1)p2(x2,y2)p3(x3,y3) A=x1*x1+y1*y1 B=x2*x2+y2*y2 C=x3*x3+y3*y3 G=(y3-y2)*x1+(y1-y3)*x2+(y2-y1)*x3 X=((B-C)*y1+(C-A)*y2+(A-B)*y3)/(2*G) Y=((C-B)*x1+(A-C)*x2+(B-A)*x3)/(2*G)

import java.math.BigDecimal; import java.util.Scanner; public class Main {public static void main(String[] args) { Scanner cin=new Scanner(System.in); BigDecimal A,B,C,G; BigDecimal x1,x2,x3,y1,y2,y3,x0,y0; BigDecimal X,Y; int t; t=cin.nextInt(); while(t--> 0) { x1=cin.nextBigDecimal(); y1=cin.nextBigDecimal(); x2=cin.nextBigDecimal(); y2=cin.nextBigDecimal(); x3=cin.nextBigDecimal(); y3=cin.nextBigDecimal(); x0=cin.nextBigDecimal(); y0=cin.nextBigDecimal(); A=x1.multiply(x1).add(y1.multiply(y1)); B=x2.multiply(x2).add(y2.multiply(y2)); C=x3.multiply(x3).add(y3.multiply(y3)); G=BigDecimal.valueOf(1); G=y3.subtract(y2).multiply(x1).add(y1.subtract(y3).multiply(x2)).add(y2.subtract(y1).multiply(x3)); X=B.subtract(C).multiply(y1).add(C.subtract(A).multiply(y2)).add(A.subtract(B).multiply(y3)).divide(BigDecimal.valueOf(2)); Y=C.subtract(B).multiply(x1).add(A.subtract(C).multiply(x2)).add(B.subtract(A).multiply(x3)).divide(BigDecimal.valueOf(2)); x0=x0.multiply(G); y0=y0.multiply(G); x1=x1.multiply(G); y1=y1.multiply(G); BigDecimal a=x0.subtract(X).multiply(x0.subtract(X)).add( y0.subtract(Y).multiply(y0.subtract(Y))); BigDecimal b=x1.subtract(X).multiply(x1.subtract(X)).add( y1.subtract(Y).multiply(y1.subtract(Y))); if(a.compareTo(b)> 0) System.out.println("Accepted"); else System.out.println("Rejected"); } } }