Submission #356420

#	Time	Username	Problem	Language	Result	Execution time	Memory
356420		blue	Triangles (CEOI18_tri)	C++17	35 / 100	13 ms	512 KiB

tri

#include "trilib.h"
#include <iostream>
using namespace std;

/*
A convex hull is a set of points p[1], p[2], .... p[k] such that for every point for every i, and for every point q
not equal to p[i] or p[i+1],   p[i], p[i+1] and q are in clockwise order
*/

int main()
{
    int n = get_n();

    bool flag;
    int res = 0;

    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            if(i == j) continue;

            flag = 1;
            for(int k = 1; k <= n; k++)
            {
                if(k == i || k == j) continue;
                flag &= is_clockwise(i, j, k);
                if(!flag) break;
            }
            if(flag)
            {
                res++;
                break;
            }
        }
    }

    give_answer(res);
}

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