Submission #229774

#	Time	Username	Problem	Language	Result	Execution time	Memory
229774		Ruxandra985	Triangles (CEOI18_tri)	C++14	0 / 100	5 ms	384 KiB

tri

#include <bits/stdc++.h>
 #include "trilib.h"
using namespace std;
 
long long v[40010] , x[40010] , y[40010] , s[40010];
 
int cmp (int x , int y){
 
    return !is_clockwise(1 , x , y);
 
}
int main()
{
    long long n , i , elem , j;
    n = get_n();
 
    /// stergi citirea, folosesti get_n
 
    for (i = 1 ; i <= n ; i++)
        v[i] = i;
 
    sort (v + 2 , v + n + 1 , cmp);
 
    /*for (i = 1 ; i <= n ; i++){
        fprintf (fout,"%d\n" , v[i]);
    }*/
 
    v[n + 1] = 1;
    s[1] = v[1];
    s[2] = v[2];
    elem = 2;
    for (j = 3 ; j <= n ; j++){
        while (elem >= 2 && is_clockwise (s[elem - 1] , s[elem] , v[j]))
            elem--;
        s[++elem] = v[j];
    }
 
 
    while (elem >= 2 && is_clockwise (s[elem - 1] , s[elem] , s[1]))
        elem--;
 
    while (elem >= 2 && is_clockwise (s[elem] , s[1] , s[2]))
        elem--;
 
    elem = max(elem , 3LL);
 
   give_answer((int)elem);
 
 
    return 0;
}

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