【圣诞树】

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include<Windows.h>
#define PI 3.14159265359
#define T x + sl * r * cosf(th), y + sl * r * sin(th)
float X, Y;
float cir(float x, float y, float r) {
    return sqrtf((x - X) * (x - X) + (y - Y) * (y - Y)) - r;
}
float un(float d1, float d2) {
    return d1 < d2 ? d1 : d2;
}
float f(float x, float y, float th, float sl, int n) {
    float d = 0.0f;
    for (float r = 0.0f; r < 0.8f; r += 0.02f)
        d = un(d, cir(T, 0.05f * sl * (0.95f - r)));
    if (n > 0)
        for (int t = -1; t <= 1; t += 2) {
            float tt = th + t * 1.8f, ss = sl * 0.9f;
            for (float r = 0.2f; r < 0.8f; r += 0.1f) 
        d = un(d, f(T, tt, ss * 0.5f, n - 1)), ss *= 0.8f;
        }
    return d;
}
int main(int argc, char *argv[]) {
  system("color A");
    int n = argc > 1 ? atoi(argv[1]) : 3;
    for (Y = 0.8f; Y > 0.0f; Y -= 0.02f, putchar('\n'))
        for (X = -0.35f; X < 0.35f; X += 0.01f) 
      putchar(f(0, 0, PI * 0.5f, 1.0f, n) < 0 ? '*' : ' ');
}