src/data-structures/line-container.hpp

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• Last update: 2025-07-19 14:29:34+09:00
• Include: #include "src/data-structures/line-container.hpp"

Verified with

• verify/data-structures/line-container/line_add_get_min.test.cpp

Code

#pragma once

/**
 * Author: Teetat T.
 * Description: Line Container (Minimize).
 * Time: O(\log N)
 */

struct Line{
	static bool querymode;
    ll m,c;
    mutable ll p;
    Line(ll m,ll c):m(m),c(c),p(0){}
    Line(ll p):m(0),c(0),p(p){}
    bool operator<(const Line &o)const{
        return querymode?p<o.p:m>o.m;
    }
};

bool Line::querymode=false;

struct LineContainer:multiset<Line>{
    ll div(ll a,ll b){
        return a/b-((a^b)<0&&a%b);
    }
    bool isect(iterator x,iterator y){
        if(y==end())return x->p=LINF,false;
        if(x->m==y->m)x->p=x->c<=y->c?LINF:-LINF;
        else x->p=div(x->c-y->c,y->m-x->m);
        return x->p>=y->p;
    }
    void add(ll m,ll c){
        auto x=insert(Line(m,c)),y=next(x);
        while(isect(x,y))y=erase(y);
        if((y=x)!=begin()&&isect(--x,y))isect(x,erase(y));
        while((y=x)!=begin()&&(--x)->p>=y->p)isect(x,erase(y));
    }
    ll get(ll x){
        if(empty())return LINF;
        Line::querymode=true;
        auto l=lower_bound(Line(x));
        Line::querymode=false;
        return l->m*x+l->c;
    }
};

#line 2 "src/data-structures/line-container.hpp"

/**
 * Author: Teetat T.
 * Description: Line Container (Minimize).
 * Time: O(\log N)
 */

struct Line{
	static bool querymode;
    ll m,c;
    mutable ll p;
    Line(ll m,ll c):m(m),c(c),p(0){}
    Line(ll p):m(0),c(0),p(p){}
    bool operator<(const Line &o)const{
        return querymode?p<o.p:m>o.m;
    }
};

bool Line::querymode=false;

struct LineContainer:multiset<Line>{
    ll div(ll a,ll b){
        return a/b-((a^b)<0&&a%b);
    }
    bool isect(iterator x,iterator y){
        if(y==end())return x->p=LINF,false;
        if(x->m==y->m)x->p=x->c<=y->c?LINF:-LINF;
        else x->p=div(x->c-y->c,y->m-x->m);
        return x->p>=y->p;
    }
    void add(ll m,ll c){
        auto x=insert(Line(m,c)),y=next(x);
        while(isect(x,y))y=erase(y);
        if((y=x)!=begin()&&isect(--x,y))isect(x,erase(y));
        while((y=x)!=begin()&&(--x)->p>=y->p)isect(x,erase(y));
    }
    ll get(ll x){
        if(empty())return LINF;
        Line::querymode=true;
        auto l=lower_bound(Line(x));
        Line::querymode=false;
        return l->m*x+l->c;
    }
};

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