18pts bus error马蜂良好求条

#include <iostream>
#include <algorithm>
#include <vector>
#include <unordered_map>
using namespace std;

typedef long long ll;
const ll N=1e5+5;
unordered_map<ll,ll> mp;
struct p{
    ll l,r,h;
    ll tag;
    bool operator<(const p t)const {
        return h<t.h;
    }
};
struct node{
    ll l,r,len,tag;
} tr[N<<5];
ll n,ans;
ll pos_x[N<<1],tot;
vector<p> line;
void build(int u,ll l,ll r){
    tr[u].l=l,tr[u].r=r;
    tr[u].len=tr[u].tag=0;
    if (l==r) return;
    int mid=(l+r)/2;
    build(u<<1,l,mid);
    build((u<<1)+1,mid+1,r);
}
void push_up(int u){
    if (tr[u].tag) tr[u].len=mp[tr[u].r+1]-mp[tr[u].l];
    else if (tr[u].l==tr[u].r) tr[u].len=0;
    else tr[u].len=tr[u<<1].len+tr[(u<<1)+1].len;
}
void upd(int u,ll l,ll r,ll v){
    if (l<=tr[u].l&&tr[u].r<=r){
        tr[u].tag+=v;
        push_up(u);
        return;
    }
    if (tr[u].l==tr[u].r) return;
    if (l<=tr[u<<1].r) upd(u<<1,l,r,v);
    if (tr[(u<<1)+1].l<=r) upd((u<<1)+1,l,r,v);
    push_up(u);
}

int main (){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    for (int i=1;i<=n;i++){
        ll x,y,xx,yy;
        cin >> x >> y >> xx >> yy;
        line.push_back((p){x,xx,y,1});
        line.push_back((p){x,xx,yy,-1});
    }
    for (auto i:line){
        pos_x[++tot]=i.l;
        pos_x[++tot]=i.r;
    }
    sort(pos_x+1,pos_x+tot+1);
    tot=unique(pos_x+1,pos_x+tot+1)-pos_x-1;
    for (int i=1;i<=tot;i++){
        mp[i]=pos_x[i];
    }
    sort(line.begin(),line.end());
    build(1,1,tot-1);
    for (int i=0;i<line.size()-1;i++){
        int l=lower_bound(pos_x+1,pos_x+tot+1,line[i].l)-pos_x;
        int r=lower_bound(pos_x+1,pos_x+tot+1,line[i].r)-pos_x-1;
        upd(1,l,r,line[i].tag);
        ans+=tr[1].len*(line[i+1].h-line[i].h);
    }
    cout << ans << endl;
    return 0;
}