Angle and Squares UVA - 1643

题意：第一象限里有一个角，把n(n<=10)个给定边长的正方形摆在这个角里，使得阴影部分面积最大

思路：参考链接

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define INF 0x3f3f3f3f
#define mod 1000000007;
using namespace std;
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
const int maxn = 10 + 2;
int main()
{
    int n;
    while(scanf("%d",&n) && n)
    {
        double x,ax,ay,bx,by;
        double l = 0,ans = 0;
        scanf("%lf%lf%lf%lf",&bx,&by,&ax,&ay);
        double k1 = ay / ax;
        double k2 = by / bx;
        if(k1 > k2) swap(k1,k2);
        for(int i = 0;i < n;i++)
        {
            scanf("%lf",&x);
            l += x;
            ans -= x * x / 2;
        }
        ax = (1 + k2) * l / (k2 - k1),ay = k1 * ax;
        bx = (1 + k1) * l / (k2 - k1),by = k2 * bx;
        ans += (ax * by - bx * ay) / 2;
        printf("%.3f\n",ans);
    }
    return 0;
}