poj 3935 Striking Ball

poj 3935 Striking Ball

#include <cstdlib>#include <iostream>#include <stdio.h>#include <cmath>#include <algorithm>#include <cstring>using namespace std;int ans,n,id,id1,id2;double W,H,w,h;double x,arg,pi=acos(-1.0),k,b,in,eps=1e-6;struct brick{       double x,y,w,h;       int p;};brick a[1000];bool visit[1000],up;int main(){    int i,j,s,p,q;    double x0,y0,x1,y1,nx1,ny1;    while(scanf("%lf%lf%lf%lf%d",&W,&H,&w,&h,&n)&&W+H+w+h+n)    {         for(i=0;i<n;i++)         { scanf("%lf%lf%d",&a[i].x,&a[i].y,&a[i].p); a[i].w=w; a[i].h=h;         }         a[n].x=a[n].y=a[n].p=0;         a[n].w=W;         a[n].h=H;         memset(visit,false,sizeof(visit));         scanf("%lf%lf",&x,&arg);         arg=arg*pi/180.000;         k=tan(arg);          b=-k*x;         x1=x;         y1=0;         id1=n;         id2=0;         up=true;         ans=0;         while(true)         { in=(double)1000000000*(double)1000000000; for(i=0;i<=n;i++) {        x0=a[i].x;        y0=k*x0+b;        if(y0<=a[i].y+a[i].h&&y0>=a[i].y)        {if((up&&y0>y1+eps)||(!up&&y0<y1-eps)){   if(in>(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1))   {       in=(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1);       id1=i;       id2=3;       nx1=x0;       ny1=y0;   }}        }        x0=a[i].x+a[i].w;        y0=k*x0+b;        if(y0<=a[i].y+a[i].h&&y0>=a[i].y)        { if((up&&y0>y1+eps)||(!up&&y0<y1-eps)) {     if(in>(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1))     {         in=(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1);         id1=i;         id2=1;         nx1=x0;         ny1=y0;     } }        }        y0=a[i].y;        x0=(y0-b)/k;        if(x0<=a[i].x+a[i].w&&x0>=a[i].x)        { if((up&&y0>y1+eps)||(!up&&y0<y1-eps)) {     if(in>(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1))     {         in=(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1);         id1=i;         id2=0;         nx1=x0;         ny1=y0;     } }        }        y0=a[i].y+a[i].h;        x0=(y0-b)/k;        if(x0<=a[i].x+a[i].w&&x0>=a[i].x)        { if((up&&y0>y1+eps)||(!up&&y0<y1-eps)) {     if(in>(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1))     {         in=(x0-x1)*(x0-x1)+(y0-y1)*(y0-y1);         id1=i;         id2=2;         nx1=x0;         ny1=y0;     } }        } } if(id1==n&&id2==0)    break; if(id1<n)     ans+=a[id1].p; if(id2==0) {    x0=x1;    y0=2*a[id1].y-y1;    if(nx1==x0)      k=(double)1000000000*(double)100000000;    else      k=(ny1-y0)/(nx1-x0);    b=y0-k*x0;    up=!up; } else if(id2==2) {    x0=x1;    y0=2*(a[id1].y+a[id1].h)-y1;    if(nx1==x0)       k=(double)1000000000*(double)100000000;    else       k=(ny1-y0)/(nx1-x0);    b=y0-k*x0;    up=!up; } else if(id2==1) {      y0=y1;      x0=2*(a[id1].x+a[id1].w)-x1;      if(nx1==x0)         k=(double)1000000000*(double)100000000;      else         k=(ny1-y0)/(nx1-x0);      b=y0-k*x0; } else if(id2==3) {      y0=y1;      x0=2*a[id1].x-x1;      if(nx1==x0)        k=(double)1000000000*(double)100000000;      else         k=(ny1-y0)/(nx1-x0);      b=y0-k*x0; } x1=nx1; y1=ny1; if(id1<n) {    for(j=id1;j<n;j++)       a[j]=a[j+1];    n--;    if(n==0)        break; }         }         printf("%dn",ans);    }    return 0;}