src/geometry/sideOf.h

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• Last update: 2025-07-19 20:33:24+09:00

Depends on

• src/geometry/Point.h

Required by

• src/geometry/PointInsideHull.h
• src/geometry/PolygonUnion.h

Code

/**
 * Author: Ulf Lundstrom
 * Date: 2009-03-21
 * License: CC0
 * Source:
 * Description: Returns where $p$ is as seen from $s$ towards $e$. 1/0/-1 $\Leftrightarrow$ left/on line/right.
 * If the optional argument $eps$ is given 0 is returned if $p$ is within distance $eps$ from the line.
 * P is supposed to be Point<T> where T is e.g. double or long long.
 * It uses products in intermediate steps so watch out for overflow if using int or long long.
 * Usage:
 * 	bool left = sideOf(p1,p2,q)==1;
 * Status: tested
 */
#pragma once

#include "src/geometry/Point.h"

template<class P>
int sideOf(P s, P e, P p) { return sgn(s.cross(e, p)); }

template<class P>
int sideOf(const P& s, const P& e, const P& p, double eps) {
	auto a = (e-s).cross(p-s);
	double l = (e-s).dist()*eps;
	return (a > l) - (a < -l);
}

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/site-packages/onlinejudge_verify/documentation/build.py", line 71, in _render_source_code_stat
    bundled_code = language.bundle(stat.path, basedir=basedir, options={'include_paths': [basedir]}).decode()
                   ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/site-packages/onlinejudge_verify/languages/cplusplus.py", line 187, in bundle
    bundler.update(path)
    ~~~~~~~~~~~~~~^^^^^^
  File "/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/site-packages/onlinejudge_verify/languages/cplusplus_bundle.py", line 312, in update
    raise BundleErrorAt(path, i + 1, "#pragma once found in a non-first line")
onlinejudge_verify.languages.cplusplus_bundle.BundleErrorAt: src/geometry/sideOf.h: line 14: #pragma once found in a non-first line

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