day5 HDU 2899 Strange fuction

写好公式三分就可以了，注意精度设置

#include"iostream"#include"iomanip"#include"math.h"using namespace std;double F(double x,double y){    return 6*x*x*x*x*x*x*x+8*x*x*x*x*x*x+7*x*x*x+5*x*x-y*x;}double find(double y){    double l,r,mid,mmid,p,q;    l=0; r=100;    while(l+0.00001<r)    {        mid=(l+r)/2.0;        mmid=(mid+r)/2.0;        p=F(mid,y);        q=F(mmid,y);        if(p<q)r=mmid;        else   l=mid;    }    return mid;}int main(){    int t;    double y,k;    cin>>t;    while(t--)    {        cin>>y;           cout<<fixed<<setprecision(4)<<F(find(y),y)<<endl;    }    return 0;}