src/geometry/HullDiameter.h

• View this file on GitHub
• Last update: 2025-07-19 20:33:24+09:00
• Link: https://codeforces.com/blog/entry/48868

Depends on

• src/geometry/Point.h

Code

/**
 * Author: Oleksandr Bacherikov, chilli
 * Date: 2019-05-05
 * License: Boost Software License
 * Source: https://codeforces.com/blog/entry/48868
 * Description: Returns the two points with max distance on a convex hull (ccw,
 * no duplicate/collinear points).
 * Status: stress-tested, tested on kattis:roberthood
 * Time: O(n)
 */
#pragma once
#include "src/geometry/Point.h"

typedef Point<ll> P;
array<P, 2> hullDiameter(vector<P> S) {
	int n = sz(S), j = n < 2 ? 0 : 1;
	pair<ll, array<P, 2>> res({0, {S[0], S[0]}});
	rep(i,0,j)
		for (;; j = (j + 1) % n) {
			res = max(res, {(S[i] - S[j]).dist2(), {S[i], S[j]}});
			if ((S[(j + 1) % n] - S[j]).cross(S[i + 1] - S[i]) >= 0)
				break;
		}
	return res.second;
}

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/HullDiameter.h: line 11: #pragma once found in a non-first line

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