Submission #1206321

#	Time	Username	Problem	Language	Result	Execution time	Memory
1206321		asli_bg	Triangles (CEOI18_tri)	C++20	35 / 100	10 ms	328 KiB

tri

#include <bits/stdc++.h>
using namespace std;
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

//#define int long long

#include "trilib.h"
 
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<bool> vb;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef vector<pll> vll;
 
typedef tree<pii,null_type,less<pii>,rb_tree_tag,
tree_order_statistics_node_update> oset;
 
#define fi first
#define se second
#define pb push_back
#define pf push_front
 
#define mid (l+r)/2
#define all(x) x.begin(),x.end()
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)
 
#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;
#define sp <<" "<<
 
#define DEBUG(x) cout<<(#x) sp x<<endl
#define carp(a,b) (((a%MOD)*(b%MOD))%MOD)
#define topla(a,b) (((a%MOD)+(b%MOD))%MOD)
 
const ll INF=1e18;
const int MAXN=92;//1e5+5;
const int MAXNN=2e5+5;
const int MOD=1e9+7;


signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int n=get_n();
    if(n==3) give_answer(3);
    else{
        int say=0;

        vb used(n+1,false);

        FORE(i,1,n+1){
            if(used[i]) continue;
            FORE(j,1,n+1){
                if(i==j) continue;

                int bir,iki;
                bir=iki=0;
                FORE(k,1,n+1){
                    if(k==i or k==j) continue;
                    if(is_clockwise(i,j,k)) bir++;
                    else iki++;

                    if(bir>0 and iki>0) break;
                }

                if(bir==0 or iki==0){
                    used[i]=used[j]=true;
                }

                if(used[i]) break;
            }
        }

        FORE(i,1,n+1) if(used[i]) say++;

        give_answer(say);
    }
}

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