Submission #459271

#	Time	Username	Problem	Language	Result	Execution time	Memory
459271		hhhhaura	Triangles (CEOI18_tri)	C++14	100 / 100	28 ms	2876 KiB

tri

#define wiwihorz
#pragma GCC optimize("Ofast")
#pragma loop-opt(on)
#include <bits/stdc++.h>
#include "trilib.h"

#define rep(i, a, b) for(int i = a; i <= b; i ++)
#define rrep(i, a, b) for(int i = b; i >= a; i--)
#define all(x) x.begin(), x.end()
#define ceil(a, b) ((a + b - 1) / (b))

#define INF 1000000000000000000
#define MOD 1000000007
#define eps (1e-9)

using namespace std;

#define int long long int
#define lld long double
#define pii pair<int, int>
#define random mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count())

#ifdef wiwihorz
#define print(a...) cerr << "Line " << __LINE__ <<": ", kout("[" + string(#a) + "] = ", a)
void kout() {cerr << endl;}
void vprint(auto L, auto R) { while(L < R)cerr << *L << " \n"[next(L) == R], ++L;}
template<class T1, class ... T2> void kout(T1 a, T2 ... e) { cerr << a << " ", kout(e...); }
#else
#define print(...) 0
#define vprint(...) 0
#endif
namespace solver {
	vector<int> v[2], hull;
	void solve() {
		int n = get_n();
		v[0].push_back(1);
		v[1].push_back(2);
		rep(i, 3, n) v[is_clockwise(2, 1, i)].push_back(i);
		rep(i, 0, 1) sort(v[i].begin() + 1, v[i].end(), 
			[](int a, int b) { return is_clockwise(1, b, a);});
		rep(tp, 0, 1) {
			for(auto i : v[tp]) {
				while(hull.size() > 1 && is_clockwise(
					hull[hull.size() - 1], i, hull[hull.size() - 2])) hull.pop_back(); 
				hull.push_back(i);
			}
		}
		int ft = 0, bk = hull.size() - 1;
		while(true) {
			bool done = 1;
			while(is_clockwise(hull[bk], hull[ft], hull[bk - 1])) {
				done = 0, bk--;
			}
			while(is_clockwise(hull[ft], hull[ft + 1], hull[bk])) {
				done = 0, ft++;
			}
			if(done) break;
		}
		give_answer(bk - ft + 1);
		return;
	}	

};
using namespace solver;
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	solve();
	return 0;
}

Compilation message (stderr)

tri.cpp:3: warning: ignoring '#pragma loop ' [-Wunknown-pragmas]
    3 | #pragma loop-opt(on)
      | 
tri.cpp:26:13: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   26 | void vprint(auto L, auto R) { while(L < R)cerr << *L << " \n"[next(L) == R], ++L;}
      |             ^~~~
tri.cpp:26:21: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
   26 | void vprint(auto L, auto R) { while(L < R)cerr << *L << " \n"[next(L) == R], ++L;}
      |                     ^~~~

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 25 / 25