Submission #1044076

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044076		UmairAhmadMirza	Svjetlost (COI18_svjetlost)	C++17	0 / 100	2 ms	348 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define point pair<int,int>
#define x first
#define y second
#define double long double
#define int long long
double const pi=3.141592653589793;


double angle(point p1,point p2){
    int deltaY = p2.y - p1.y;
    int deltaX = p2.x - p1.x;
    double dg = atan2(deltaY, deltaX) * 180 / pi;
    if(dg<0)
        dg+=360;
    return dg;}

bool check(double a1,double a2){
    if(a1<180)
        return (a2<a1) || (a2>a1+180);
    else
        return (a2>a1-180);
}
double dist(point a,point b){
    return sqrt(((a.x-b.x)*(a.x-b.x))+((a.y-b.y)*(a.y-b.y)));
}

double solve(vector<point> pts){
    int n=pts.size();
    if(n==1)
        return 0;
    else if(n==2)
        return dist(pts[0],pts[1]);
    for (int i = 0; i < n; ++i)
        pts.push_back(pts[i]);
    deque<point> v;
    v.push_back(pts[0]);
    v.push_back(pts[1]);
    v.push_back(pts[2]);
    double len=dist(pts[0],pts[1])+dist(pts[1],pts[2]);
    double maxx=len;
    int p1=0,p2=2;
    while(p1<n){
        int a1=angle(pts[p1],pts[p1+1]);
        int a2=angle(pts[p2+1],pts[p2]);
        if(p2-p1<n-1 && a1!=a2 && check(a1,a2)){
            len+=dist(pts[p2],pts[p2+1]);
            p2++;
        }
        else{
            len-=dist(pts[p1],pts[p1+1]);
            p1++;
        }
        maxx=max(maxx,len);
    }
    return maxx;
}

signed main(){
    int n;
    cin>>n;
    vector<point> pts(n);
    for (int i = 0; i < n; ++i)
        cin>>pts[i].x>>pts[i].y;
    if(angle(pts[0],pts[1])>angle(pts[0],pts[2]))
        reverse(pts.begin(), pts.end());
    cout<<fixed;
    cout<<setprecision(7)<<solve(pts)<<endl;
    return 0;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 14
• Subtask 3: 0 / 14
• Subtask 4: 0 / 29
• Subtask 5: 0 / 31