蓝桥杯：矩形面积交

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define max(x,y) ((x)>(y)?(x):(y))
#define min(x,y) ((x)<(y)?(x):(y))
int main()
{
    double a1,a2,b1,b2,a3,a4,b3,b4,s,m1,m2,n1,n2;

    scanf("%lf %lf %lf %lf",&a1,&b1,&a2,&b2);
    scanf("%lf %lf %lf %lf",&a3,&b3,&a4,&b4);
    m1=max(min(a1,a2),min(a3,a4));
    n1=min(max(b1,b2),max(b3,b4));
    m2=min(max(a1,a2),max(a3,a4));
    n2=max(min(b1,b2),min(b3,b4));
    if(m2>m1&&n1>n2)
    printf("%.2lf",(m2-m1)*(n1-n2));
    else printf("0.00");

    return 0;
}