hdu5091线段树

#include 
#include 
#include <string.h>
#include 
#include 
using namespace std;
const int maxn = 10005;
typedef int ll;
struct point{
  ll x,y;
  point(ll a=0, ll b=0){
       x=a; y=b;
  }
}P[maxn];
ll cL,cR,value,N,H,W,ynum,xnum;
struct Itree{
    ll ma[maxn*4],se[maxn*4];
    void build(ll o, ll L, ll R){
         se[o]=ma[o]=0;
         if(L==R){
             return ;
         }
         ll mid=(L+R)/2;
         build(o*2,L,mid);
         build(o*2+1,mid+1,R);
    }
    void matain(ll o){
        ma[o]=max(ma[o*2]+se[o*2],ma[o*2+1]+se[o*2+1]);
    }
    void push(ll o){
        se[o*2]+=se[o];
        se[o*2+1]+=se[o];
        se[o]=0;
    }
    void update( ll o, ll L, ll R){
         if(cL<=L&&R<=cR){
             se[o]+=value;
             return ;
         }
         ll mid =(L+R)/2;
         if(se[o]!=0){
             push(o);
         }
         if(cL<=mid) update(o*2,L,mid);
         if(cR>mid) update(o*2+1,mid+1,R);
         matain(o);
    }
}Q;
vector F[maxn];
ll X[maxn];
ll Y[maxn];
void solve(ll loc){
    ll siz=F[loc].size();
    for(ll i=0; ii){
        ll y = F[loc][i];
        cL = lower_bound(Y,Y+ynum,y-H)-Y+1;
        cR = lower_bound(Y,Y+ynum,y)-Y+1;
        Q.update(1,1,ynum);
    }
}
int main()
{

    while(scanf("%d",&N)==1){
         if(N<0) break;
         scanf("%d%d",&W,&H);
         for(ll i=0; ii){
             scanf("%d%d",&X[i],&Y[i]);
             P[i]=point(X[i],Y[i]);
         }
         sort(X,X+N);
          xnum = unique(X,X+N)-X;
         for(ll i=0; i<=xnum; ++i) F[i].clear();
         sort(Y,Y+N);
         ynum = unique(Y,Y+N)-Y;
         Q.build(1,1,ynum);
         for(ll i=0; ii){
             ll loc = lower_bound(X,X+xnum,P[i].x)-X;
             F[loc].push_back(P[i].y);
         }
         ll ans=0;
         for(ll i=0,j=0;jj){
             while(X[j]-X[i]>W) {
                 value=-1;
                 solve(i);
                 i++;
             }
             value=1;
             solve(j);
             ans=max(ans,Q.ma[1]+Q.se[1]);
         }
         printf("%d\n",ans);
    }
    return 0;
}