Submission #873365

#	Time	Username	Problem	Language	Result	Execution time	Memory
873365		Darren0724	Triangles (CEOI18_tri)	C++17	0 / 100	1 ms	348 KiB

tri

#include <bits/stdc++.h>
#include "trilib.h"


using namespace std;


int32_t main() {
    int n=get_n();
    //int cnt=0;
    //int ans=0;
    //int i=1;
    vector<int> r[2];
    //vector<int> ans[2];
    vector<int> s[2];
    for(int j=3;j<=n;j++){
        int t=is_clockwise(1,2,j);
        r[t].push_back(j);
    }
    for(int y=0;y<2;y++){
        sort(r[y].begin(),r[y].end(),[&](int a,int b){return is_clockwise(1,b,a);});
        s[y].push_back(y==0?2:1);
        for(int i:r[y]){
            while(s[y].size()>1&&is_clockwise(s[y].end()[-2],s[y].end()[-1],i)){
                s[y].pop_back();
            }
            s[y].push_back(i);
        }
    }
    
    for(int i:s[1]){
        while(s[0].size()>1&&is_clockwise(s[0].end()[-2],s[0].end()[-1],i)){
            s[0].pop_back();
        }
        s[0].push_back(i);
    }
    give_answer(s[0].size());

    return 0;
}

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