优化后的标题：校园互联新方案：10397连接教育未来

Problem E

Connect the Campus

Input: standard input

Output: standard output

Time Limit: 2 seconds



Many new buildings are under construction on the campus of the University of Waterloo.

许多新的建筑物在建造在滑铁卢大学的校园。

The university has hired bricklayers, electricians, plumbers, and a computer programmer.

学校聘请了砌砖工&＃xff0c;电工&＃xff0c;水管工&＃xff0c;和一个计算机程序员。

A computer programmer? Yes, you have been hired to ensure that each building is connected to every other building (directly or indirectly) through the campus network of communication cables.

一个计算机程序员&＃xff1f;是的&＃xff0c;你被雇佣来确保每个建筑连接到每个建筑&＃xff08;直接或间接&＃xff09;通过通讯电缆的校园网络。

We will treat each building as a point specified by an x-coordinate and a y-coordinate.

我们将把每一个建筑物作为一个点的X坐标和y坐标指定。

Each communication cable connects exactly two buildings, following a straight line between the buildings.

每个通信电缆连接两个建筑物&＃xff0c;在建筑物之间的一条直线。

Information travels along a cable in both directions.

信息沿着两个方向的电缆。

Cables can freely cross each other, but they are only connected together at their endpoints (at buildings).

电缆可以自由地相互交叉&＃xff0c;但他们只连接在一起&＃xff0c;在它们的端点&＃xff08;建筑物&＃xff09;。

You have been given a campus map which shows the locations of all buildings and existing communication cables.

你已经给了一个校园地图&＃xff0c;显示了所有建筑物和现有的通信电缆的位置。

You must not alter the existing cables.

你不能改变现有的电缆。

Determine where to install new communication cables so that all buildings are connected.

确定要安装新的通信电缆&＃xff0c;连接所有大楼。

Of course, the university wants you to minimize the amount of new cable that you use.

当然&＃xff0c;大学要你减少你使用新的电缆的数量。

【最小生成树 Prim/Kruskal&并查集】



Fig: University of Waterloo Campus 图&＃xff1a;滑铁卢大学校园



 



Input



The input file describes several test case.  The description of each test case is given below:

输入文件描述了几个测试用例。每个测试案例的描述如下&＃xff1a;

The first line of each test case contains the number of buildings N (1<&＃61;N<&＃61;750). The buildings are labeled from 1 to N.

每个测试案例的第一行包含建筑的数量N&＃xff08;1≤n≤750&＃xff09;。建筑标记从1到N&＃xff0c;

The next N lines give the x and y coordinates of the buildings.

以下N行给X和Y坐标的建筑物。

These coordinates are integers with absolute values at most 10000.

这些坐标是绝对值的整数 最多10000

No two buildings occupy the same point.

没有两个建筑占据同一点。

After that there is a line containing the number of existing cables M (0 <&＃61; M <&＃61; 1000) followed by M lines describing the existing cables.

之后有一行包含现有的电缆的数量&＃xff08;0≤m≤1000&＃xff09;随后的M行描述现有的电缆。

Each cable is represented by two integers: the building numbers which are directly connected by the cable.

每个电缆是由两个整数表示&＃xff1a;这是由电缆直接连接的门牌号码。

There is at most one cable directly connecting each pair of buildings.

至多有一个电缆直接连接每对建筑物。

Output



For each set of input, output in a single line the total length of the new cables that you plan to use, rounded to two decimal places.

对每一组输入&＃xff0c;输出一行新的电缆总长度&＃xff0c;你计划使用&＃xff0c;圆形到两位小数。