杭电ACM 三 在坐标系中的微积分

问题及代码

Problem Description

Ignatius bought a land last week, but he didn‘t know the area of the land because the land is enclosed by a parabola and a straight line. The picture below shows the area. Now given all the intersectant points shows in the picture, can you tell Ignatius the area of the land?

Note: The point P1 in the picture is the vertex of the parabola.

Input

Output

Sample Input

2
5.000000 5.000000
0.000000 0.000000
10.000000 0.000000
10.000000 10.000000
1.000000 1.000000
14.000000 8.222222

Sample Output

33.33
40.69

/*
*Copyright (c)2014,烟台大学计算机与控制工程学院
*All rights reserved.
*文件名称：team.cpp
*作    者：冷基栋
*完成日期：2015年2月16日
*版 本 号：v1.0
*/
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
    int n;
    double x1,x2,x3,y1,y2,y3;
    cin>>n;
    while (n--)
    {
        double k,s;
        cin>>x1>>y1>>x2>>y2>>x3>>y3;
        k = (y2-y1)/((x2-x1)*(x2-x1));
        s = (k*(x3-x1)*(x3-x1)*(x3-x1))/3 - k*(x2-x1)*(x2-x1)*(x2-x1)/3 + y1*(x3-x2);
        s -= (y3+y2)*(x3-x2)/2;
        cout <<setiosflags(ios::fixed)<<setprecision(2)<< s << endl;
    }

    return 0;
}

运行结果：

知识点总结：

微积分and方程

学习心得：
好好学习 天天向上

杭电ACM 三 在坐标系中的微积分

原文：http://blog.csdn.net/ljd939952281/article/details/43851901