Posted on 2010-08-17 14:09
Brian 阅读(258)
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POJ
Description
Fred Mapper is considering purchasing some land in Louisiana to build his house on. In the process of investigating the land, he learned that the state of Louisiana is actually
shrinking by 50 square miles each year, due to erosion caused by the Mississippi River. Since Fred is hoping to live in this house the rest of his life, he needs to know if his land is going to be lost to erosion.
After doing more research, Fred has learned that the land that is being lost forms a semicircle. This semicircle is part of a circle centered at
(0,0), with the line that bisects the circle being the X axis. Locations below the X axis are in the water. The semicircle has an area of 0 at the beginning of year 1. (Semicircle illustrated in the Figure.)
Input
The first line of input will be a positive integer indicating how many data sets will be included (N). Each of the next N lines will contain the X and Y Cartesian coordinates of the land Fred is considering. These will be floating point numbers measured in miles. The Y coordinate will be non-negative. (0,0) will not be given.
Output
For each data set, a single line of output should appear. This line should take the form of: “Property N: This property will begin eroding in year Z.” Where N is the data set (counting from 1), and Z is the first year (start from 1) this property will be within the semicircle AT THE END OF YEAR Z. Z must be an integer. After the last data set, this should print out “END OF OUTPUT.”
把题意弄明白，就知道这道题是水题了，由坐标 (0,0) 开始，以半圆为形状每年侵蚀50 平方 miles ，问你从 (0,0) 开始到 (x,y) 结束需要多长时间，水题不需要太关注效率，所以变量定义上没有深究，其他不解释。
编译器 C + + :
#include <iostream>
using namespace std;
#define PI 3.1415926
int main()
{
int n,i=0,year;
double x,y,area;
cin>>n;
while (i<n)
{
cin>>x>>y;
area = 0.5 * PI * (x*x+y*y); // semicircle area equation
year = area/50;
printf("Property %d: This property will begin eroding in year %d.\n",i+1,year+1);
i++;
}
printf("END OF OUTPUT.\n");
return 0;
}