src/geometry/int/parall_cross.hpp

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Last update: 2026-01-07 21:13:29+09:00
Include: #include "src/geometry/int/parall_cross.hpp"

Depends on

src/template.hpp

Code

#include "../../template.hpp"

optional<P> parall_cross(P a1,P a2,P b1,P b2){
    auto [x1,y1]=a1;
    auto [x2,y2]=a2;
    auto [x3,y3]=b1;
    auto [x4,y4]=b2;
    auto [ax0,ax1]=minmax(x1,x2);
    auto [ay0,ay1]=minmax(y1,y2);
    auto [bx0,bx1]=minmax(x3,x4);
    auto [by0,by1]=minmax(y3,y4);
    int ix0=max(ax0,bx0),ix1=min(ax1,bx1);
    int iy0=max(ay0,by0),iy1=min(ay1,by1);
    if(ix0>ix1||iy0>iy1) return nullopt;
    return {{ix0,iy0}};
}

#line 2 "src/template.hpp"
#include <bits/stdc++.h>
using namespace std;
#define si(a) (long)a.size()
#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(int)(n);++i)
template<typename S,typename F> bool chmin(S&a,F b){return b<a?(a=b,1):0;}
template<typename S,typename F> bool chmax(S&a,F b){return b>a?(a=b,1):0;}
bool _=(ios::sync_with_stdio(0),cin.tie(0),cout<<fixed<<setprecision(16),0);
#line 2 "src/geometry/int/parall_cross.hpp"

optional<P> parall_cross(P a1,P a2,P b1,P b2){
    auto [x1,y1]=a1;
    auto [x2,y2]=a2;
    auto [x3,y3]=b1;
    auto [x4,y4]=b2;
    auto [ax0,ax1]=minmax(x1,x2);
    auto [ay0,ay1]=minmax(y1,y2);
    auto [bx0,bx1]=minmax(x3,x4);
    auto [by0,by1]=minmax(y3,y4);
    int ix0=max(ax0,bx0),ix1=min(ax1,bx1);
    int iy0=max(ay0,by0),iy1=min(ay1,by1);
    if(ix0>ix1||iy0>iy1) return nullopt;
    return {{ix0,iy0}};
}