1.00 1.00 3.00 3.00 2.00 2.00 4.00 4.00
5.00 5.00 13.00 13.00 4.00 4.00 12.50 12.50

1.00
56.25

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<stdlib.h>
int cmp(const void *a,const void *b)
{
 return *(double *)a>*(double *)b?1:-1;
}
int main()
{
 double s,l,h;
 double x[4],y[4];
 double x1,y1,x2,x3,x4,y2,y3,y4;
 while(~scanf("%lf%lf%lf%lf%lf%lf%lf%lf",&x1,&y1,&x2,&y2,&x3,&y3,&x4,&y4))
 {
  x[0]=x1;x[1]=x2;x[2]=x3;x[3]=x4;
  y[0]=y1;y[1]=y2;y[2]=y3;y[3]=y4;
  qsort(x,4,sizeof(x[0]),cmp);
  qsort(y,4,sizeof(y[0]),cmp);
  l=fabs(x2-x1)+fabs(x4-x3)-(x[3]-x[0]);
  h=fabs(y2-y1)+fabs(y4-y3)-(y[3]-y[0]);
  s=l*h;
  if(l<=0||h<=0)//推断不重叠的时候 为零由于题目有要求是精确到两位小数 
  s=0.00;
  printf("%.2lf\n",s);
 }
 return 0;
}