Luo Gu P4344 [SHOI2015] brain-dong therapeutic equipment

Description of the meaning of problems

Maintenance sequence, supports the following operations:

• 0 lr: l ~ r assigned to the 0
• 1 l1 r1 l2 r2: the l1 ~ r1 1 in replacement of l2 ~ r2 0, discard excess
• 2 lr: interrogation maximum continuous length of 1 in the l ~ r

Problem solution ideas

Keduo Li tree violence assignment inquiry

Code

#include <set>
#include <iostream>
#include <algorithm>
#define IT set<Node>::iterator
typedef long long ll;
using std::set;
int n,m,op,l0,r0,l1,r1,x,y;
struct Node {
    int l,r;
    mutable int v;
    Node(int L,int R,ll V):l(L),r(R),v(V) {}
    bool operator<(const Node& x) const { return l<x.l; }
};
set<Node> s;
inline void print() {
    for (IT it=s.begin();it!=s.end();++it) {
        std::cout<<it->l<<' '<<it->r<<' '<<it->v<<'\n';
    }
}
inline IT split(const int& pos) {
    IT it=s.lower_bound(Node(pos,0,0));
    if (it!=s.end()&&it->l==pos) return it;
    --it; int L=it->l,R=it->r; ll V=it->v; s.erase(it);
    s.insert(Node(L,pos-1,V));
    return s.insert(Node(pos,R,V)).first;
}
inline void assign(const int& l,const int& r,const int& va) {
    IT itr=split(r+1),itl=split(l); s.erase(itl,itr); s.insert(Node(l,r,va));
}
inline void modify(const int& l0,const int& r0,const int& l1,const int& r1) {
    IT itr=split(r0+1),itl=split(l0); int sum=0;
    for (IT it=itl;it!=itr;++it) if (it->v) sum+=it->r-it->l+1;
    s.erase(itl,itr); s.insert(Node(l0,r0,0));
    if (!sum) return;
    itr=split(r1+1),itl=split(l1);
    for (IT it=itl;it!=itr;++it) if (!it->v) {
        if (sum>=it->r-it->l+1) sum-=it->r-it->l+1,it->v=1;
        else assign(it->l,it->l+sum-1,1),sum=0;
    }
}
inline int query(const int& l,const int& r,int res=0,int xx=0) {
    for (IT itr=split(r+1),itl=split(l);itl!=itr;++itl)
        if (itl->v) res=std::max(res,xx),xx=0;
        else xx+=itl->r-itl->l+1;
    return res=std::max(res,xx);
}
int main() {
    std::ios::sync_with_stdio(0); std::cin.tie(0); std::cout.tie(0);
    std::cin>>n>>m; s.insert(Node(1,n,1));
    for (register int i=1;i<=m;++i) {
        std::cin>>op>>l0>>r0;
        if (op==0) assign(l0,r0,0);
        else if (op==1) std::cin>>l1>>r1,modify(l0,r0,l1,r1);
        else if (op==2) std::cout<<query(l0,r0)<<'\n';
    }
}