BZOJ3490 : Pa2011 Laser Pool
与横线以及竖线的交点个数很容易求,那么只要求出横线竖线交点与运动轨迹的交点数即可。
运动轨迹可以划分成若干条贯穿边界的斜线,对于第一条和最后一条,可以用bitset暴力统计。
对于中间的部分,斜线都是完整的,可以FFT预处理。
时间复杂度$O(n\log n+\frac{nq}{32})$。
#include<cstdio> #include<cmath> #include<algorithm> using namespace std; typedef unsigned int U; const int N=100010,M=10010,L=262150; int n,m,cb,ce,i,j,ab[N*2],arb[N*2],rab[N*2],rarb[N*2],g[65540]; char a[N],b[N]; struct Que{int x,y,vx,vy,t,ans;}e[M]; inline int popcount(U x){return g[x>>16]+g[x&65535];} struct BIT{ U v[N/32+5]; void clr(){for(int i=0;i<=cb;i++)v[i]=0;} U get(int x){return v[x>>5]>>(x&31)&1;} void set(int x,U y){if((v[x>>5]>>(x&31)&1)^y)v[x>>5]^=1U<<(x&31);} void shl(int x,int y){ int A=y>>5,B=y&31,C=(32-B)&31,D=x>>5,E=(D<<5)+31; for(int i=x;i<=E;i++)set(i,get(i+y)); for(int i=D+1;i<=cb;i++){ v[i]=v[i+A]>>B; if(C)v[i]|=v[i+A+1]<<C; } } void copy(int x,int y,const BIT&p){for(int i=x;i<=y;i++)v[i]=p.v[i];} void And(int x,int y,const BIT&p){for(int i=x;i<=y;i++)v[i]&=p.v[i];} int count(int x,int y){ int A=x>>5,B=y>>5,C,ret=0; if(A==B){ for(int i=x;i<=y;i++)if(v[A]>>(i&31)&1)ret++; return ret; } for(int i=A+1;i<B;i++)ret+=popcount(v[i]); C=(A<<5)+31; for(int i=x;i<=C;i++)if(v[A]>>(i&31)&1)ret++; C=B<<5; for(int i=C;i<=y;i++)if(v[B]>>(i&31)&1)ret++; return ret; } }bA,bB,brA,brB,tA,tB; inline void read(int&a){ char c;bool f=0;a=0; while(!((((c=getchar())>='0')&&(c<='9'))||(c=='-'))); if(c!='-')a=c-'0';else f=1; while(((c=getchar())>='0')&&(c<='9'))(a*=10)+=c-'0'; if(f)a=-a; } namespace FFT{ int k,j,pos[L]; const double pi=acos(-1.0); struct comp{ double r,i;comp(double _r=0,double _i=0){r=_r,i=_i;} comp operator+(const comp&x){return comp(r+x.r,i+x.i);} comp operator-(const comp&x){return comp(r-x.r,i-x.i);} comp operator*(const comp&x){return comp(r*x.r-i*x.i,r*x.i+i*x.r);} }a[L],ra[L],b[L],rb[L],c[L]; void FFT(comp a[],int n,int t){ for(int i=1;i<n;i++)if(i<pos[i])swap(a[i],a[pos[i]]); for(int d=0;(1<<d)<n;d++){ int m=1<<d,m2=m<<1; double o=pi*2/m2*t;comp _w(cos(o),sin(o)); for(int i=0;i<n;i+=m2){ comp w(1,0); for(int j=0;j<m;j++){ comp&A=a[i+j+m],&B=a[i+j],t=w*A; A=B-t;B=B+t;w=w*_w; } } } if(t==-1)for(int i=0;i<n;i++)a[i].r/=n; } void work(){ for(k=1;k<=n||k<=m;k<<=1);k<<=1; j=__builtin_ctz(k)-1; for(i=0;i<k;i++)pos[i]=pos[i>>1]>>1|((i&1)<<j); for(i=1;i<=n;i++)a[i].r=ra[n-i+1].r=::a[i]; for(i=1;i<=m;i++)b[i].r=rb[m-i+1].r=::b[i]; FFT(a,k,1),FFT(ra,k,1),FFT(b,k,1),FFT(rb,k,1); for(i=0;i<k;i++)c[i]=a[i]*b[i]; FFT(c,k,-1); for(i=1;i<=n+m;i++)ab[i]=(int)(c[i].r+0.5); for(i=0;i<k;i++)c[i]=a[i]*rb[i]; FFT(c,k,-1); for(i=1;i<=n+m;i++)arb[i]=(int)(c[i].r+0.5); for(i=0;i<k;i++)c[i]=ra[i]*b[i]; FFT(c,k,-1); for(i=1;i<=n+m;i++)rab[i]=(int)(c[i].r+0.5); for(i=0;i<k;i++)c[i]=ra[i]*rb[i]; FFT(c,k,-1); for(i=1;i<=n+m;i++)rarb[i]=(int)(c[i].r+0.5); } } namespace Solve{ bool a[N],b[N]; int sa[N],sb[N]; int cnt,idx[4][N],idy[4][N]; int tot,st[N*8],en[N*8],v[N*8],pos[N*8],cur,q[N*8],sw[N*8];long long sl[N*8]; struct E{int sx,sy,ex,ey,len,w,d,nxt;}f[N*8]; inline bool check(int x,int y){return b[x]&&a[y];} inline int abs(int x){return x>0?x:-x;} inline int&getid(int x,int y,int d){ if(y==1||y==n)return idx[d][x]; return idy[d][y]; } inline void makerev(int x){ f[x].sx=f[x-1].ex; f[x].sy=f[x-1].ey; f[x].ex=f[x-1].sx; f[x].ey=f[x-1].sy; f[x].w=f[x-1].w; f[x].d=(f[x-1].d+2)&3; } inline int getnxt(int x,int y,int d){ if(d==0){ if(x<m&&y==n)return getid(x,y,(d+1)&3); if(y==n)return getid(x,y,(d+2)&3); return getid(x,y,(d+3)&3); } if(d==2){ if(x>1&&y==1)return getid(x,y,(d+1)&3); if(y==1)return getid(x,y,(d+2)&3); return getid(x,y,(d+3)&3); } if(d==1){ if(x<m&&y==1)return getid(x,y,(d+3)&3); if(y==1)return getid(x,y,(d+2)&3); return getid(x,y,(d+1)&3); } if(x>1&&y==n)return getid(x,y,(d+3)&3); if(y==n)return getid(x,y,(d+2)&3); return getid(x,y,(d+1)&3); } inline int cal(int x,int t,int n,int*s){ if(x+t<=n)return s[x+t]-s[x-1]; t-=n-x; int ret=s[n-1]-s[x-1]; ret+=t/(n+n-2)*(s[n]+s[n-1]-s[1]); t%=n+n-2; if(t<n)return ret+s[n]-s[n-t-1]; return ret+s[n]-s[1]+s[t-n+2]; } inline int search(int L,int r,int x){ int l=L,t=L-1,mid; while(l<=r)if(sl[mid=(l+r)>>1]-sl[L-1]<=x)l=(t=mid)+1;else r=mid-1; return t; } inline void ask(int x,int y,int t,int p){ int&ans=e[p].ans; ans=cal(x,t,m,sb)+cal(y,t,n,sa); int ex=m,ey=y-x+m; if(ey>n)ey=n,ex=x-y+n; int d=ex-x; if(t<=d){ tA.copy(y>>5,cb,bA); tB.copy(x>>5,cb,bB); tB.shl(0,x); tA.shl(0,y); tA.And(0,t>>5,tB); ans-=tA.count(0,t); return; } if(d){ tA.copy(y>>5,cb,bA); tB.copy(x>>5,cb,bB); tB.shl(0,x); tA.shl(0,y); tA.And(0,(d-1)>>5,tB); ans-=tA.count(0,d-1); } t-=d; int o=getnxt(ex,ey,0); int l=st[v[o]],r=en[v[o]]; o=pos[o]; int u=search(o,r,t); ans-=sw[u]-sw[o-1]; t-=sl[u]-sl[o-1]; o=u+1; if(o>r){ ans-=t/(sl[r]-sl[l-1])*(sw[r]-sw[l-1]); t%=sl[r]-sl[l-1]; u=search(l,r,t); ans-=sw[u]-sw[l-1]; t-=sl[u]-sl[l-1]; o=u+1; } o=q[o]; x=f[o].sx,y=f[o].sy; if(f[o].d==0){ tA.copy(y>>5,cb,bA); tB.copy(x>>5,cb,bB); } if(f[o].d==1){ y=n-y+1; tA.copy(y>>5,cb,brA); tB.copy(x>>5,cb,bB); } if(f[o].d==2){ x=m-x+1; y=n-y+1; tA.copy(y>>5,cb,brA); tB.copy(x>>5,cb,brB); } if(f[o].d==3){ x=m-x+1; tA.copy(y>>5,cb,bA); tB.copy(x>>5,cb,brB); } tB.shl(0,x); tA.shl(0,y); tA.And(0,t>>5,tB); ans-=tA.count(0,t); } void work(int*A,int*B){ for(i=1;i<=n;i++)sa[i]=sa[i-1]+a[i],bA.set(i,a[i]),brA.set(n-i+1,a[i]); for(i=1;i<=m;i++)sb[i]=sb[i-1]+b[i],bB.set(i,b[i]),brB.set(m-i+1,b[i]); cnt=0; for(i=1;i<m;i++){ cnt++; f[cnt].sx=i,f[cnt].sy=1; f[cnt].ex=m,f[cnt].ey=m-i+1; if(f[cnt].ey>n)f[cnt].ey=n,f[cnt].ex=n-1+i; f[cnt].w=B[m-i+2]; f[cnt].d=0; makerev(++cnt); } for(i=2;i<n;i++){ cnt++; f[cnt].sx=1,f[cnt].sy=i; f[cnt].ex=m,f[cnt].ey=m-1+i; if(f[cnt].ey>n)f[cnt].ey=n,f[cnt].ex=n-i+1; f[cnt].w=B[m+i]; f[cnt].d=0; makerev(++cnt); } for(i=2;i<=m;i++){ cnt++; f[cnt].sx=i,f[cnt].sy=1; f[cnt].ex=1,f[cnt].ey=i; if(f[cnt].ey>n)f[cnt].ey=n,f[cnt].ex=i+1-n; f[cnt].w=A[i+1]; f[cnt].d=3; makerev(++cnt); } for(i=2;i<n;i++){ cnt++; f[cnt].sx=m,f[cnt].sy=i; f[cnt].ex=1,f[cnt].ey=m+i-1; if(f[cnt].ey>n)f[cnt].ey=n,f[cnt].ex=m+i-n; f[cnt].w=A[i+m]; f[cnt].d=3; makerev(++cnt); } for(i=1;i<=cnt;i++){ f[i].len=abs(f[i].sx-f[i].ex); f[i].w-=check(f[i].ex,f[i].ey); getid(f[i].sx,f[i].sy,f[i].d)=i; } for(i=1;i<=cnt;i++)f[i].nxt=getnxt(f[i].ex,f[i].ey,f[i].d); cur=tot=0; for(i=1;i<=cnt;i++)v[i]=0; for(i=1;i<=cnt;i++)if(!v[i]){ st[++tot]=cur+1; for(j=i;!v[j];j=f[j].nxt)v[q[++cur]=j]=tot; en[tot]=cur; } for(i=1;i<=cnt;i++)sl[i]=sl[i-1]+f[q[i]].len,sw[i]=sw[i-1]+f[q[i]].w,pos[q[i]]=i; } } int main(){ for(i=1;i<65536;i++)g[i]=g[i>>1]+(i&1); read(n),read(m); scanf("%s%s",a+1,b+1); for(i=1;i<=n;i++)a[i]-='0'; for(i=1;i<=m;i++)b[i]-='0'; read(ce); for(i=1;i<=ce;i++)read(e[i].x),read(e[i].y),read(e[i].vx),read(e[i].vy),read(e[i].t); FFT::work(); cb=(n>m?n:m)>>5; for(i=1;i<=n;i++)Solve::a[i]=a[i]; for(i=1;i<=m;i++)Solve::b[i]=b[i]; Solve::work(ab,arb); for(i=1;i<=ce;i++)if(e[i].vx==1&&e[i].vy==1)Solve::ask(e[i].x,e[i].y,e[i].t,i); for(i=1;i<=n;i++)Solve::a[i]=a[n-i+1]; for(i=1;i<=m;i++)Solve::b[i]=b[i]; Solve::work(rab,rarb); for(i=1;i<=ce;i++)if(e[i].vx==1&&e[i].vy==-1)Solve::ask(e[i].x,n-e[i].y+1,e[i].t,i); for(i=1;i<=n;i++)Solve::a[i]=a[i]; for(i=1;i<=m;i++)Solve::b[i]=b[m-i+1]; Solve::work(arb,ab); for(i=1;i<=ce;i++)if(e[i].vx==-1&&e[i].vy==1)Solve::ask(m-e[i].x+1,e[i].y,e[i].t,i); for(i=1;i<=n;i++)Solve::a[i]=a[n-i+1]; for(i=1;i<=m;i++)Solve::b[i]=b[m-i+1]; Solve::work(rarb,rab); for(i=1;i<=ce;i++)if(e[i].vx==-1&&e[i].vy==-1)Solve::ask(m-e[i].x+1,n-e[i].y+1,e[i].t,i); for(i=1;i<=ce;i++)printf("%d\n",e[i].ans); return 0; }