ALDS1_5_C コッホ曲線をC++で解いてみた[AIZU ONLINE JUDGE]

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

struct Point {
    double x;
    double y;
};

void print_point(Point a) { cout << fixed << setprecision(8) << a.x << " " << a.y << endl; }

void koch(int d, Point p, Point q) {
    if(d == 0) {
        return;
    }

    Point s, u, t;
    s.x = (2 * p.x + q.x) / 3.0;
    s.y = (2 * p.y + q.y) / 3.0;
    t.x = (p.x + 2 * q.x) / 3.0;
    t.y = (p.y + 2 * q.y) / 3.0;

    double ang = M_PI * 60 / 180.0; //度をラジアンに変換
    u.x = (t.x - s.x) * cos(ang) - (t.y - s.y) * sin(ang) + s.x;
    u.y = (t.x - s.x) * sin(ang) + (t.y - s.y) * cos(ang) + s.y;

    koch(d - 1, p, s);
    print_point(s);
    koch(d - 1, s, u);
    print_point(u);
    koch(d - 1, u, t);
    print_point(t);
    koch(d - 1, t, q);
}

int main() {
    int n;
    cin >> n;

    Point s1, s2;
    s1.x = 0;
    s1.y = 0;
    s2.x = 100;
    s2.y = 0;

    print_point(s1);
    koch(n, s1, s2);
    print_point(s2);

    return 0;
}