Rectangles

坐标排序是关键

#include<stdio.h> 
#include<algorithm>
using namespace std;

int main()
{
	int  i, j, k, n, m;
	double x[5], y[5], a[5], b[5], s;
	while(scanf("%lf%lf%lf%lf%lf%lf%lf%lf",&x[1], &y[1], &x[2], &y[2], &x[3], &y[3], &x[4], &y[4]) == 8)
	{
		s = 0;
		for(int i = 1; i <= 4; ++ i)
		{
			a[i] = x[i];
			b[i] = y[i];
		}
		sort(x + 1, x + 5);
		sort(y + 1, y + 5);
		if(x[3] > a[1] && x[3] > a[2] || x[3] > a[3] && x[3] > a[4] ||
			y[3] > b[1] && y[3] > b[2] || y[3] > b[3] && y[3] > b[4]);
		else
			s = (x[3] - x[2]) * (y[3] - y[2]);
		
		printf("%.2f\n", s);
	}
	
	return 0;
}