src/geometry/CircleLine.h

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• Last update: 2025-07-19 20:33:24+09:00
• Link: https://vlecomte.github.io/cp-geo.pdf

Depends on

• src/geometry/Point.h

Code

/**
 * Author: Victor Lecomte, chilli
 * Date: 2019-10-29
 * License: CC0
 * Source: https://vlecomte.github.io/cp-geo.pdf
 * Description: Finds the intersection between a circle and a line.
 * Returns a vector of either 0, 1, or 2 intersection points.
 * P is intended to be Point<double>.
 * Status: unit tested
 */

#pragma once

#include "src/geometry/Point.h"

template<class P>
vector<P> circleLine(P c, double r, P a, P b) {
	P ab = b - a, p = a + ab * (c-a).dot(ab) / ab.dist2();
	double s = a.cross(b, c), h2 = r*r - s*s / ab.dist2();
	if (h2 < 0) return {};
	if (h2 == 0) return {p};
	P h = ab.unit() * sqrt(h2);
	return {p - h, p + h};
}

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/CircleLine.h: line 12: #pragma once found in a non-first line

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