UESTC 人在地上走，锅从天上来（线段区间维护和点更新）

https://acm.uestc.edu.cn/problem/ren-zai-di-shang-zou-guo-cong-tian-shang-lai/description 

将点当成左闭右开的线段，然后每次查是否有位置填，也就是一个点维护和一个线段维护就可以了

#include <bits/stdc++.h>

using namespace std;

const int maxn= 1e5+9;

int res[maxn];

int flag;
struct rt{
    int x,y;
    int nx,ny;
}a[maxn];
int b[maxn*2];

struct xx{
    int sum,ls,rs;
    int lazy;
}dat[maxn*8];

int dd[maxn*8];
int dian[maxn*8];
int dianlazy[maxn*8];
int lazy[maxn*8];

void pushUpS(int k){
    if(dat[k<<1].rs&&dat[k<<1|1].ls){
        dat[k].sum=dat[k<<1].sum+dat[k<<1|1].sum-1;
    }
    else{
        dat[k].sum=dat[k<<1].sum+dat[k<<1|1].sum;
    }
    dat[k].rs=dat[k<<1|1].rs;
    dat[k].ls=dat[k<<1].ls;
}

void pushUpd(int k){
    dian[k]=dian[k<<1]+dian[k<<1|1];
}

void pushUp(int k){
    dd[k]=dd[k<<1]+dd[k<<1|1];
}

void pushDown(int k,int l,int r){
    int mid=(l+r)>>1;
    dd[k<<1]=mid-l+1;
    dd[k<<1|1]=r-mid;
    lazy[k<<1]=lazy[k<<1|1]=1;
    lazy[k]=0;
}

void updata(int a,int b,int l,int r,int k){
    if(a<=l&&r<=b){
        dd[k]=r-l+1;lazy[k]=1;return;
    }
    if(lazy[k])pushDown(k,l,r);
    int mid=(l+r)>>1;
    if(a<=mid)updata(a,b,l,mid,k<<1);
    if(b>mid)updata(a,b,mid+1,r,k<<1|1);
    pushUp(k);
}

int query(int a,int b,int l,int r,int k){
    if(a<=l&&r<=b)return dd[k];
    if(lazy[k])pushDown(k,l,r);
    int mid=(l+r)>>1;
    int ans=0;
    if(a<=mid)ans+=query(a,b,l,mid,k<<1);
    if(b>mid)ans+=query(a,b,mid+1,r,k<<1|1);
    return ans;
}

void updataS(int a,int b,int l,int r,int k){
    if(dat[k].lazy)return;
    if(a<=l&&r<=b){
        dat[k].sum=1;
        dat[k].ls=dat[k].rs=1;
        dat[k].lazy=1;
        return ;
    }
    int mid=(l+r)>>1;
    if(a<=mid)updataS(a,b,l,mid,k<<1);
    if(b>mid)updataS(a,b,mid+1,r,k<<1|1);
    pushUpS(k);
}

void updatad(int a,int b,int l,int r,int k,int x){
    if(dianlazy[k])return;
    if(a<=l&&r<=b){
        dian[k]=x;
        if(x==0)dianlazy[k]=1;
        return;
    }
    int mid=(l+r)>>1;
    if(a<=mid)updatad(a,b,l,mid,k<<1,x);
    if(b>mid)updatad(a,b,mid+1,r,k<<1|1,x);
    pushUpd(k);
}

int main(){
    ios::sync_with_stdio(false);
    int n;cin>>n;
    int tt=0;
    for(int i=1;i<=n;i++){
        cin>>a[i].x>>a[i].y;
        b[++tt]=a[i].x;
        b[++tt]=a[i].y;
    }
    sort(b+1,b+1+tt);
    int num=unique(b+1,b+1+tt)-(b+1);
    for(int i=1;i<=n;i++){
        a[i].nx=lower_bound(b+1,b+1+num,a[i].x)-b;
        a[i].ny=lower_bound(b+1,b+1+num,a[i].y)-b;
    }
    int ans=0;
    for(int i=1;i<=n;i++){
        int x=query(a[i].nx,a[i].ny,1,num,1);
        updata(a[i].nx,a[i].ny,1,num,1);
        if(a[i].nx!=a[i].ny){
            updataS(a[i].nx,a[i].ny-1,1,num,1);
            updatad(a[i].nx,a[i].ny,1,num,1,0);
        }
        if(x==0){
            ans++;
            if(a[i].nx==a[i].ny){
                updatad(a[i].nx,a[i].nx,1,num,1,1);
            }
        }
        else{
            ans=dat[1].sum+dian[1];
        }
        res[i]=ans;
    }
    for(int i=1;i<=n;i++){
        cout<<res[i];
        if(i<n)cout<<" ";
        else cout<<endl;
    }
    return 0;
}