src/geometry/lineDistance.h

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

Depends on

• src/geometry/Point.h

Code

/**
 * Author: Ulf Lundstrom
 * Date: 2009-03-21
 * License: CC0
 * Source: Basic math
 * Description:\\
\begin{minipage}{75mm}
Returns the signed distance between point p and the line containing points a and b.
Positive value on left side and negative on right as seen from a towards b. a==b gives nan.
P is supposed to be Point<T> or Point3D<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.
Using Point3D will always give a non-negative distance. For Point3D, call .dist on the result of the cross product.
\end{minipage}
\begin{minipage}{15mm}
\includegraphics[width=\textwidth]{src/geometry/lineDistance}
\end{minipage}
 * Status: tested
 */
#pragma once

#include "src/geometry/Point.h"

template<class P>
double lineDist(const P& a, const P& b, const P& p) {
	return (double)(b-a).cross(p-a)/(b-a).dist();
}

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/lineDistance.h: line 19: #pragma once found in a non-first line

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