hdu 2899 Strange fuction 模拟退火

求  F(x) = 6 * x^7+8*x^6+7*x^3+5*x^2-y*x (0 <= x <=100)的最小值

模拟退火，每次根据温度随机下个状态，再根据温度转移

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<cmath>
#define inf (double)0x3f3f3f3f3f3f3f3fll
using namespace std;
double y;
double cal(double x){
	return 6*pow(x,7.0)+8*pow(x,6.0)+7*pow(x,3.0)+5*pow(x,2.0)-y*x;
}
double Rand(){
	return (rand()%1000)/1000.0;
}
double work(){
	double T=100,now=0;
	double fnow=cal(now);
	double minf=min(inf,fnow);
	while(T>0.0000001){
		double nxt=now+T*(Rand()*2-1);
		if(nxt>=0&&nxt<=100){
			double fnxt=cal(nxt);
			double dE=fnow-fnxt;
			if((dE>0)||(exp(dE/T))>Rand()){
				now=nxt;fnow=fnxt;}
		}
		T*=0.99;
	}
	return fnow;
}
int main(){
	srand(20001101);
	int T;
	scanf("%d",&T);
	while(T--){
		scanf("%lf",&y);
		printf("%0.4lf\n",work());
	}
}