hdu 2056

ps:    - -惭愧。。。是套用一个大神的计算方法来做的.....下面是代码

代码：

#include "stdio.h"
#include "stdlib.h"
#include "math.h"
int cmp(const void *a,const void *b){
 return *(double *)a>*(double *)b?1:-1;
}
int main(){
 int n=1,i;
 double s,l,h,x[4],y[4],x1,x2,x3,x4,y1,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) s=0.00;
        printf("%.2lf\n",s);
  }
 return 0;
}