CF617C.Watering Flowers

普及/提高-

通过率:0%

时间限制:2.00s

内存限制:256MB

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题目描述

A flowerbed has many flowers and two fountains.

You can adjust the water pressure and set any values _r_1(_r_1 ≥ 0) and _r_2(_r_2 ≥ 0), giving the distances at which the water is spread from the first and second fountain respectively. You have to set such _r_1 and _r_2 that all the flowers are watered, that is, for each flower, the distance between the flower and the first fountain doesn't exceed _r_1, or the distance to the second fountain doesn't exceed _r_2. It's OK if some flowers are watered by both fountains.

You need to decrease the amount of water you need, that is set such _r_1 and _r_2 that all the flowers are watered and the _r_12 + _r_22 is minimum possible. Find this minimum value.

一个花坛中有很多花朵和两个喷泉。

你可以调节水压,为第一个和第二个喷泉分别设定任意非负值 r1r_1(r1≥0r_1 \geq 0)和 r2r_2(r2≥0r_2 \geq 0),表示水从对应喷泉喷洒出的最大距离。你需要选定这样的 r1r_1 和 r2r_2,使得所有花朵都被浇灌到,即:对每一朵花,它到第一个喷泉的距离不超过 r1r_1,或者它到第二个喷泉的距离不超过 r2r_2。允许某些花朵同时被两个喷泉浇灌。

你需要最小化用水量,即选定满足上述条件的 r1r_1 和 r2r_2,使得 r12+r22r_1^2 + r_2^2 尽可能小。求该最小值。

输入格式

The first line of the input contains integers n, _x_1, _y_1, _x_2, _y_2 (1 ≤ n ≤ 2000,  - 107 ≤ _x_1, _y_1, _x_2, _y_2 ≤ 107) — the number of flowers, the coordinates of the first and the second fountain.

Next follow n lines. The i-th of these lines contains integers x__i and y__i ( - 107 ≤ x__i, y__i ≤ 107) — the coordinates of the i-th flower.

It is guaranteed that all n + 2 points in the input are distinct.

输入的第一行包含整数 nn、x1x_1、y1y_1、x2x_2、y2y_2(1 ≤ n ≤ 20001 ≤ n ≤ 2000,−107 ≤ x1, y1, x2, y2 ≤ 107-10^7 ≤ x_1, y_1, x_2, y_2 ≤ 10^7)——分别表示花的数量,以及第一座和第二座喷泉的坐标。

接下来是 nn 行。其中第 ii 行包含整数 xix_i 和 yiy_i(−107 ≤ xi, yi ≤ 107-10^7 ≤ x_i, y_i ≤ 10^7)——表示第 ii 朵花的坐标。

保证输入中的全部 n+2n+2 个点互不相同。

输出格式

Print the minimum possible value _r_12 + _r_22. Note, that in this problem optimal answer is always integer.

输出最小可能的值 r12+r22r_1^2 + r_2^2。注意,在本题中,最优解始终为整数。

输入输出样例

  • 输入#1

    2 -1 0 5 3
    0 2
    5 2

    输出#1

    6
  • 输入#2

    4 0 0 5 0
    9 4
    8 3
    -1 0
    1 4

    输出#2

    33

说明/提示

The first sample is (_r_12 = 5, _r_22 = 1): The second sample is (_r_12 = 1, _r_22 = 32):

第一个样例是(r12=5r_{12} = 5,r22=1r_{22} = 1):
第二个样例是(r12=1r_{12} = 1,r22=32r_{22} = 32):

输入解题思路,AI测评打分。不知道怎么写?

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