英语翻译DescriptionA sailboat has many forces acting on it.This

英语翻译
Description
A sailboat has many forces acting on it.This allows it to sail in many different directions,even if the wind is not blowing in the desired direction.In order for the boat to be easily controlled,however,certain forces must be balanced.
Suppose the wind is blowing from the north and the boat is facing west.Above the water,the blowing wind hits the sails,and because of the way that they are angled,pushes the boat to the southwest.The keel extends deep below the water.The water resistance on the keel creates a counterforce pushing the boat northward.Ideally,the northward force on the keel will counteract the southward component of the force on the sails,so that the boat will move to the west.
A problem can arise if the centre of the sails (called the Centre of Effort,or CE) is not directly above the centre of the keel (called the Centre of Lateral Resistance,or CLR).In general,the boat can pivot about the centre of the keel.If the sails are too far forward of the keel,the wind will push the bow (the front) of the boat southwards,and the boat will turn towards the south.If the sails are too far aft of (behind) the keel,the wind will push the stern (the back) southwards,and the boat will turn towards the north.Ideally,the sails and keel are balanced so that the boat sails in a straight line.
In this problem,you will examine a side view of the boat to determine whether the CE is above the CLR.The CE is defined as the centroid of the part of the boat above the waterline.The CLR is defined as the centroid of the part of the boat below the waterline.The centroid of a polygon is the unique point such that any line passing through it divides the polygon into two halves of equal area.
Input
The first line of input will contain a single integer n specifying the number of points along the outline of the side view of the boat.The following n lines will each contain two integers:the x and y coordinate of a point along the outline.The points will be given in order along the outline.The x axis (i.e.the line y = 0) represents the waterline.Assume that the boat faces in the direction of increasing x coordinates.
Output
If the CE is forward of the CLR,print the line:
CE is forward of CLR by N units.
If the CE is aft of (behind) the CLR,print the line:
CE is aft of CLR by N units.
In both cases,replace the N with the difference in the x coordinates of the CE and CLR to two decimal places.If the x coordinates of the CE and CLR are equal,print the line:
Balanced.
Sample Input
7
0 1
2 3
4 1
4 -3
2 -3
2 -1
0 -1
Sample Output
CE is aft of CLR by 0.50 units
比较长，说出大致意思也行

描述
帆船有许多部队采取行动.这使得它在许多不同的航行方向,即使没有风是吹在希望的方向.为了使船容易控制,但是,某些势力必须是平衡的.
假设风在吹,来自北方和该船正面临西方.以上的水,风的吹安打船帆,由于道路,他们倾斜,推动了船的西南.龙骨延伸深处的水.耐水性的龙骨创建一个反作用力推动船北上.理想的情况是,向北队龙骨将抵消部分南下部队的船帆,使船将转向西方.
可能出现的问题,如果该中心的帆（称为该中心的努力,或行政长官）没有直接以上的中心,龙骨（称为中心横向电阻,或使用CLR ） .一般情况下,该船可以枢轴关于该中心的龙骨.如果船帆是太远着的龙骨,风将推动弓（前端）的船向南,与该船将转向南方.如果船帆是太远后面的（后面）的龙骨,风将推动斯特恩（背部）向南,与该船将转向北部地区.最理想的是,帆船和龙骨的平衡,使该船的帆直线.
在此问题,您将审查侧面的船,以确定是否行政长官首先是在CLR .行政长官会同行政会议的定义是心的一部分,该船水线以上.在CLR定义为心的一部分,该船在水线之下.心是一个多边形的独特点,例如,任何线穿过它分为两半多边形到平等领域.
输入
第一线的投入将包含一个整数n指定若干要点沿大纲侧面的船.以下ñ线将每个包含两个整数：在X和Y坐标点沿线的大纲.积分将在沿线的大纲.X轴（即线为y = 0 ）代表水线.承担该船面临方向增加x坐标.
输出
如果行政长官具有前瞻性的CLR ,打印的行：
行政长官是前瞻性的使用CLR由N单位.
如果行政长官是后面的（后面）在CLR ,打印的行：
后面的行政长官是由N单位使用CLR .
在这两种情况下,将n的差异的X坐标的CE和CLR到小数点后两位.如果在X坐标的CE和CLR是平等的,打印的行：
平衡.
采样输入
7
0 1
3月2日
4月1日
4 -3
2 -3
2 -1
0 -1
示例输出
后面的行政长官是由0.50单位使用CLR