A11079. Five Dimensional Points
编程题
普及/提高-
知识点
题目描述
You are given set of $n$ points in 5-dimensional space. The points are labeled from $1$ to $n$ . No two points coincide.
We will call point $a$ bad if there are different points $b$ and $c$ , not equal to $a$ , from the given set such that angle between vectors  and  is acute (i.e. strictly less than ). Otherwise, the point is called good.
The angle between vectors  and  in 5-dimensional space is defined as , where  is the scalar product and  is length of .
Given the list of points, print the indices of the good points in ascending order.
We will call point $a$ bad if there are different points $b$ and $c$ , not equal to $a$ , from the given set such that angle between vectors  and  is acute (i.e. strictly less than ). Otherwise, the point is called good.
The angle between vectors  and  in 5-dimensional space is defined as , where  is the scalar product and  is length of .
Given the list of points, print the indices of the good points in ascending order.
输入格式
The first line of input contains a single integer $n$ ( $1<=n<=10^{3}$ ) — the number of points.
The next $n$ lines of input contain five integers $a_{i},b_{i},c_{i},d_{i},e_{i}$ ( $|a_{i}|,|b_{i}|,|c_{i}|,|d_{i}|,|e_{i}|<=10^{3}$ ) — the coordinates of the i-th point. All points are distinct.
The next $n$ lines of input contain five integers $a_{i},b_{i},c_{i},d_{i},e_{i}$ ( $|a_{i}|,|b_{i}|,|c_{i}|,|d_{i}|,|e_{i}|<=10^{3}$ ) — the coordinates of the i-th point. All points are distinct.
输出格式
First, print a single integer $k$ — the number of good points.
Then, print $k$ integers, each on their own line — the indices of the good points in ascending order.
Then, print $k$ integers, each on their own line — the indices of the good points in ascending order.
输入输出样例
输入 #1
6 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1
输出 #1
1 1
输入 #2
3 0 0 1 2 0 0 0 9 2 0 0 0 5 9 0
输出 #2
0
说明/提示
In the first sample, the first point forms exactly a  angle with all other pairs of points, so it is good.
In the second sample, along the cd plane, we can see the points look as follows:

We can see that all angles here are acute, so no points are good.
In the second sample, along the cd plane, we can see the points look as follows:

We can see that all angles here are acute, so no points are good.