Submission #383510

#	Time	Username	Problem	Language	Result	Execution time	Memory
383510		maximath_1	Triangles (CEOI18_tri)	C++11	0 / 100	1 ms	384 KiB

tri

#include "trilib.h"
#include <iostream>
#include <assert.h>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
using namespace std;

void getConvexHull(){
	int n = get_n();

	vector<int> v(n - 1, 0);
	iota(v.begin(), v.end(), 2);
	stable_sort(v.begin(), v.end(), [&](int a, int b){
		return is_clockwise(1, a, b);
	});

	vector<int> ch;
	ch.push_back(1); ch.push_back(v[0]);
	for(int i = 1; i < v.size(); i ++){
		while(ch.size() >= 2 && !is_clockwise(ch[ch.size() - 2], ch.back(), v[i])) ch.pop_back();
		ch.push_back(v[i]);
	}

	give_answer(ch.size());
}

int main(){
	getConvexHull();
}

Compilation message (stderr)

tri.cpp: In function 'void getConvexHull()':
tri.cpp:21:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  for(int i = 1; i < v.size(); i ++){
      |                 ~~^~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 25