light oj 1297 Largest Box

#include<iostream>#include<cstring>#include<cstdio>#include<math.h>using namespace std;double l,w;double g(double x){return 12*x*x-4*(l+w)*x+l*w;}int main(){int t;double left,right,mid;int k=1;scanf("%d",&t);while(t--){scanf("%lf%lf",&l,&w);printf("Case %d: ",k);k++;if(l>w)right=w/2.0;elseright=l/2.0;left=0.0;while(right-left>1e-8){mid=(right+left)/2.0;if(g(mid)<0)right=mid;elseleft=mid;}printf("%.7lf\n",(l-2*mid)*(w-2*mid)*mid);}return 0;} 下面是方程组法

#include<iostream>#include<cstring>#include<math.h>#include<cstdio>using namespace std;int main(){int t;scanf("%d",&t);int k=1;while(t--){double l,w;scanf("%lf%lf",&l,&w);printf("Case %d: ",k);k++;double x,a,b,c;a=12.0;b=-4.0*(w+l);c=w*l*1.0;x=(-b-sqrt(b*b-4*a*c))/(2*a);printf("%.7lf\n",(l-2*x)*(w-2*x)*x);}return 0;}