hdu4445 CRAZY TANK 2012金华赛区现场赛D题

#include<iostream>
#include<cmath>
#include<cstdio>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
#define inf 0x3f3f3f3f
const double pi=acos(-1.0);
const double g=9.8;

int main()
{
int n,ans,sum,i,flag;
double h,agl,l1,l2,r1,r2,v[205],l;
while(scanf("%d",&n)&&n)
{
scanf("%lf%lf%lf%lf%lf",&h,&l1,&r1,&l2,&r2);
for(i=0;i<n;i++)
scanf("%lf",&v[i]);
agl=0;
ans=0;
while(agl<=pi)
{
sum=0;
for(i=0,flag=1;i<n;i++)
{
//l=vx*t (gt+vy)2-vy2=2gh
l=v[i]*sin(agl)*(sqrt(v[i]*v[i]*cos(agl)*cos(agl)+2*g*h)-v[i]*cos(agl))/g;
if(l>=l2&&l<=r2)
{
flag=0;
break;
}
else if(l>=l1&&l<=r1)
sum++;
}
if(flag) ans=max(ans,sum);
agl+=(pi/1000);
}
printf("%d\n",ans);
}
return 0;
}