题目:
Strange fuction
Time Limit : 2000/1000ms (Java/Other) Memory Limit : 32768/32768K (Java/Other)
Total Submission(s) : 144 Accepted Submission(s) : 72
2<br>100<br>200
-74.4291<br>-178.8534
代码:#include<iostream>
#include<stdio.h>
#include<cmath>
using namespace std;
double f(double x,long long y)
{
return (42*x*x*x*x*x*x+48*x*x*x*x*x+21*x*x+10*x-y);
}
int main()
{
int t;
cin>>t;
while(t--)
{
double mid=50.0,m=0.0,n=100.0,x,s;
long long y;
cin>>y;
while(fabs(f(mid,y))>1e-5)
{
if((f(mid,y)>0))
{
n=mid;
mid=(m+n)/2;
}
else if(f(mid,y)<0)
{
m=mid;
mid=(m+n)/2;
}
}
x=mid;
s=6*x*x*x*x*x*x*x+8*x*x*x*x*x*x+7*x*x*x+5*x*x-y*x;
printf("%.4lf\n",s);
}
return 0;
}
导数为0的点就去最小值