Submission #1044172

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044172		vjudge1	Svjetlost (COI18_svjetlost)	C++17	14 / 100	121 ms	11604 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long double
#define point pair<int,int>
#define x first
#define y second
int const pi=3.141592653589793;
int const oe=180;

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

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

int 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]);
    }
    int len=dist(pts[0],pts[1])+dist(pts[1],pts[2]);
    int maxx=len;
    int p1=0,p2=2;
    int a=0,b=2;
    while(p1<n){
        int a1=angle(pts[p1],pts[p1+1]);
        int a2=angle(pts[p2+1],pts[p2]);
        // cout<<a1<<' '<<a2<<endl;
        if(p2+1<p1+n && a1!=a2 && check(a1,a2)){
            len+=dist(pts[p2],pts[p2+1]);
            p2+=1;
        }
        else{
            len-=dist(pts[p1],pts[p1+1]);
            p1+=1;
        }
        if(len>maxx){
            maxx=len;
            a=p1,b=p2;
        }
        // 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;
    cout<<fixed;
    cout<<setprecision(10)<<solve(pts)<<endl;
    return 0;
}

Compilation message (stderr)

svjetlost.cpp: In function 'long double solve(std::vector<std::pair<long double, long double> >)':
svjetlost.cpp:41:9: warning: variable 'a' set but not used [-Wunused-but-set-variable]
   41 |     int a=0,b=2;
      |         ^
svjetlost.cpp:41:13: warning: variable 'b' set but not used [-Wunused-but-set-variable]
   41 |     int a=0,b=2;
      |             ^

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