BZOJ 1935: [Shoi2007]Tree 园丁的烦恼 [树状数组 离线 离散化]

Posted 2020-09-01 Candy?

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刚才我还在郁闷网上怎么没人用$CDQ$分治做

突然发现根本没有时间序....

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
const int N=3e6+5;
inline int read(){
    char c=getchar();int x=0,f=1;
    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1; c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘; c=getchar();}
    return x*f;
}
int n,Q,c[N],mp[N];
int m,qid;
struct Operation{
    int x,y,v,id;
    int qid,op;
    Operation():op(0){}
    Operation(int x,int y,int v,int id,int qid,int op):
        x(x),y(y),v(v),id(id),qid(qid),op(op){}
    bool operator <(const Operation &r)const{
        return x==r.x?op<r.op:x<r.x;
    }
}a[N];
void devideQuery(){
    int x1=read()-1,y1=read()-1,x2=read(),y2=read();
    mp[++mp[0]]=y1;mp[++mp[0]]=y2;
    qid++;
    m++;a[m]=Operation(x2,y2,1,m,qid,1);
    m++;a[m]=Operation(x1,y2,-1,m,qid,1);
    m++;a[m]=Operation(x2,y1,-1,m,qid,1);
    m++;a[m]=Operation(x1,y1,1,m,qid,1);
}
void iniMP(){
    sort(mp+1,mp+1+mp[0]);
    int p=0;
    mp[++p]=mp[1];
    for(int i=2;i<=mp[0];i++) if(mp[i]!=mp[i-1]) mp[++p]=mp[i];
    mp[0]=p;
}
int Bin(int v){
    int l=1,r=mp[0];
    while(l<=r){
        int mid=(l+r)>>1;
        if(v==mp[mid]) return mid;
        else if(v<mp[mid]) r=mid-1;
        else l=mid+1;
    }
    return 0;
}
inline int lowbit(int x){return x&-x;}
void add(int p,int v){for(;p<=n;p+=lowbit(p)) c[p]+=v;}
int sum(int p){
    int re=0;
    for(;p;p-=lowbit(p)) re+=c[p];
    return re;
}
int ans[N];
void solve(){
    for(int i=1;i<=m;i++){
        if(!a[i].op) add(a[i].y,1);
        else ans[a[i].qid]+=a[i].v*sum(a[i].y);
    }
    for(int i=1;i<=Q;i++) printf("%d\n",ans[i]);
}
int main(){
    freopen("in","r",stdin);
    n=read();Q=read();
    for(int i=1;i<=n;i++) a[++m].x=read(),mp[++mp[0]]=a[m].y=read();
    for(int i=1;i<=Q;i++) devideQuery();
    iniMP();
    for(int i=1;i<=m;i++) a[i].y=Bin(a[i].y);
    sort(a+1,a+1+m);
    solve();
}