mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
103 lines
2.8 KiB
C++
103 lines
2.8 KiB
C++
#include <iostream>
|
|
#include <cstdio>
|
|
#include <cstring>
|
|
#include <algorithm>
|
|
#include <cmath>
|
|
using namespace std;
|
|
const double EPS=1e-8;
|
|
const int maxn=100;
|
|
int n;
|
|
struct Point
|
|
{
|
|
double x,y;
|
|
Point (double x=0,double y=0):x(x),y(y){}
|
|
};
|
|
Point poly[maxn];
|
|
typedef Point Vector;
|
|
Vector operator + (Vector A,Vector B) {return Vector(A.x+B.x,A.y+B.y);}
|
|
Vector operator - (Point A,Point B) {return Vector(A.x-B.x,A.y-B.y);}
|
|
Vector operator * (Vector A,double p) {return Vector(A.x*p,A.y*p);}
|
|
Vector operator / (Vector A,double p) {return Vector(A.x/p,A.y/p);}
|
|
bool operator < (const Point &a,const Point &b){
|
|
return a.x < b.x ||(a.x==b.x &&a.y < b.y);
|
|
}
|
|
int dcmp (double x){
|
|
if(fabs(x)<EPS)
|
|
return 0;
|
|
else return x < 0?-1:1;
|
|
}
|
|
bool operator == (const Point &a ,const Point &b){
|
|
return dcmp(a.x-b.x) ==0 && dcmp(a.y - b.y)==0;
|
|
}
|
|
double Cross (Vector A,Vector B) {return A.x*B.y - A.y*B.x;}
|
|
double Dot (Vector A,Vector B) {return A.x*B.x + A.y*B.y;}
|
|
bool isPointOnSegment (Point p,Point a1,Point a2)
|
|
{
|
|
return dcmp ( Cross(a1-p,a2-p) )==0 && dcmp(Dot (a1-p,a2-p))<0;
|
|
}
|
|
int online(Point a,Point b,Point p)
|
|
{
|
|
Point v1,v2;
|
|
v1=p-a;v2=p-b;
|
|
if( dcmp(Cross(v1,v2))!=0) //绉涓涓0 灏变ㄧ寸嚎涓
|
|
return 0;
|
|
else
|
|
{
|
|
if(dcmp(min(a.x,b.x)- p.x)<=0 && dcmp(p.x-max(a.x,b.x))<=0
|
|
&&dcmp(min(a.y,b.y)- p.y)<=0 &&dcmp( p.y-max(a.y,b.y))<=0)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
}
|
|
int isPointInPolygon (Point p)
|
|
{
|
|
int wn=0;
|
|
for(int i=0;i<n;i++){
|
|
if( online (poly[i], poly[(i+1)%n],p)) return 0;
|
|
int k=dcmp (Cross(poly[(i+1)%n]-poly[i],p-poly[i]));
|
|
int d1=dcmp(poly[i].y-p.y);
|
|
int d2=dcmp(poly[(i+1)%n].y-p.y);
|
|
if(k>0 && d1<=0 && d2>0) wn++;
|
|
if(k<0 && d2<=0 && d1>0) wn--;
|
|
}
|
|
if(wn!=0) return 1;
|
|
return 0;
|
|
}
|
|
int main()
|
|
{
|
|
double v,b,g;
|
|
while (scanf("%lf %lf %lf",&v,&b,&g),v||b||g)
|
|
{
|
|
v=-v;
|
|
scanf("%d",&n);
|
|
bool flag=false;
|
|
int i;
|
|
double minx=1e12,maxx=-1e12,maxy=-1e12;
|
|
for(i=0;i<n;i++)
|
|
{
|
|
scanf("%lf %lf",&poly[i].x,&poly[i].y);
|
|
if(poly[i].x>maxx) maxx=poly[i].x;
|
|
if(poly[i].x<minx) minx=poly[i].x;
|
|
if(poly[i].y>maxy) maxy=poly[i].y;
|
|
}
|
|
double t;
|
|
for(int i=0;;i++)
|
|
{
|
|
t=i*0.001;
|
|
Point temp;
|
|
temp.x=v*t;temp.y=b*t-0.5*g*t*t;
|
|
if( isPointInPolygon(temp) )
|
|
{
|
|
printf("%.2f\n",t-EPS);
|
|
flag=true;
|
|
break;
|
|
}
|
|
if(!g && temp.y>maxy) break;
|
|
if(temp.y<0) break;
|
|
}
|
|
if(!flag) printf("Miss!\n");
|
|
}
|
|
return 0;
|
|
}
|