absolute_garbage.cpp

#include <cstdio>
#include <cmath>

using ld = long double;

struct base {
    ld x, y;

    base(ld _x = 0, ld _y = 0): x(_x), y(_y) {}

    base operator *(const base& ot) const {
        return {x * ot.x - y * ot.y, x * ot.y + y * ot.x};
    }
};

const int N = 1 << 6;
base angles[N];

int main() {
    const ld pi = acosl(-1);
    const base root{cos(2 * pi / N), sin(2 * pi / N)};
    angles[0] = 1;
    for (int i = 1; i < N; ++i) {
        angles[i] = angles[i - 1] * root;
        if (!(i & 7)) {
            angles[i] = {cos(2 * pi / N * i), sin(2 * pi / N * i)};
            if (i == N / 4) {
                printf("%d\n", (int)(2 * pi / N * i == pi / 2));
                printf(" angles: %.5lf %.5lf\n", (double)(2 * pi / N * i), (double)(pi / 2));
                printf("cosines: %.5lf %.5lf\n", (double)cos(2 * pi / N * i), (double)cos(pi / 2));
            }
        }
    }

    return 0;
}