#include "data_structure/swag.hpp"
#pragma once #include<stack> #include<tuple> #include<cmath> #include"../alga/maybe.hpp" /** * @brief SWAG(Queue) */ template<typename T,typename F> class swag{ std::stack<std::pair<T,T>>front,back; F f; public: swag(F f=F()):f(f){} inline int size(){ return front.size()+back.size(); } inline int empty(){ return front.empty()&&back.empty(); } void push(T val){ if(back.empty()){ back.emplace(val,val); }else{ back.emplace(val,f(back.top().second,val)); } } void pop(){ if(front.empty()){ while(!back.empty()){ const T val=back.top().first; back.pop(); if(front.empty())front.emplace(val,val); else front.emplace(val,f(val,front.top().second)); } } front.pop(); } maybe<T> fold(){ if(front.empty()&&back.empty())return maybe<T>(); else if(front.empty()||back.empty())return front.empty()?back.top().second:front.top().second; return f(front.top().second,back.top().second); } };
#line 2 "data_structure/swag.hpp" #include<stack> #include<tuple> #include<cmath> #line 2 "alga/maybe.hpp" #include<cassert> /** * @brief Maybe * @see https://ja.wikipedia.org/wiki/%E3%83%A2%E3%83%8A%E3%83%89_(%E3%83%97%E3%83%AD%E3%82%B0%E3%83%A9%E3%83%9F%E3%83%B3%E3%82%B0)#Maybe%E3%83%A2%E3%83%8A%E3%83%89 */ template<typename T> struct maybe{ bool _is_none; T val; maybe():_is_none(true){} maybe(T val):_is_none(false),val(val){} T unwrap()const{ assert(!_is_none); return val; } T unwrap_or(T e)const{ return _is_none?e:val; } bool is_none()const{return _is_none;} bool is_some()const{return !_is_none;} }; template<typename T,typename F> auto expand(F op){ return [&op](const maybe<T>& s,const maybe<T>& t){ if(s.is_none())return t; if(t.is_none())return s; return maybe<T>(op(s.unwrap(),t.unwrap())); }; } #line 6 "data_structure/swag.hpp" /** * @brief SWAG(Queue) */ template<typename T,typename F> class swag{ std::stack<std::pair<T,T>>front,back; F f; public: swag(F f=F()):f(f){} inline int size(){ return front.size()+back.size(); } inline int empty(){ return front.empty()&&back.empty(); } void push(T val){ if(back.empty()){ back.emplace(val,val); }else{ back.emplace(val,f(back.top().second,val)); } } void pop(){ if(front.empty()){ while(!back.empty()){ const T val=back.top().first; back.pop(); if(front.empty())front.emplace(val,val); else front.emplace(val,f(val,front.top().second)); } } front.pop(); } maybe<T> fold(){ if(front.empty()&&back.empty())return maybe<T>(); else if(front.empty()||back.empty())return front.empty()?back.top().second:front.top().second; return f(front.top().second,back.top().second); } };