#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[]) {
int n = argc > 1 ? atoi(argv[1]) : 4;
for (int j = 1; j <= n; j++) {
int s = 1 << j, k = (1 << n) - s, x;
for (int y = s - j; y >= 0; y--, putchar(‘\n‘)) {
for (x = 0; x < y + k; x++) printf(" ");
for (x = 0; x + y < s; x++) printf("%c ", ‘!‘ ^ y & x);
for (x = 1; x + y < s; x++) printf("%c ", ‘!‘ ^ y & (s - y - x - 1));
}
}
}

*********************************************************************************************

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#define PI 3.14159265359

float sx, sy;

float sdCircle(float px, float py, float r) {
float dx = px - sx, dy = py - sy;
return sqrtf(dx * dx + dy * dy) - r;
}

float opUnion(float d1, float d2) {
return d1 < d2 ? d1 : d2;
}

#define T px + scale * r * cosf(theta), py + scale * r * sin(theta)

float f(float px, float py, float theta, float scale, int n) {
float d = 0.0f;
for (float r = 0.0f; r < 0.8f; r += 0.02f)
d = opUnion(d, sdCircle(T, 0.05f * scale * (0.95f - r)));

if (n > 0)
for (int t = -1; t <= 1; t += 2) {
float tt = theta + t * 1.8f;
float ss = scale * 0.9f;
for (float r = 0.2f; r < 0.8f; r += 0.1f) {
d = opUnion(d, f(T, tt, ss * 0.5f, n - 1));
ss *= 0.8f;
}
}

return d;
}

int main(int argc, char* argv[]) {
int n = argc > 1 ? atoi(argv[1]) : 3;
for (sy = 0.8f; sy > 0.0f; sy -= 0.02f, putchar(‘\n‘))
for (sx = -0.35f; sx < 0.35f; sx += 0.01f)
putchar(f(0, 0, PI * 0.5f, 1.0f, n) < 0 ? ‘*‘ : ‘ ‘);
}

*********************************************************************************************

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PI 3.14159265359f

float sx, sy;

typedef float Mat[4][4];
typedef float Vec[4];

void scale(Mat* m, float s) {
Mat temp = { {s,0,0,0}, {0,s,0,0 }, { 0,0,s,0 }, { 0,0,0,1 } };
memcpy(m, &temp, sizeof(Mat));
}

void rotateY(Mat* m, float t) {
float c = cosf(t), s = sinf(t);
Mat temp = { {c,0,s,0}, {0,1,0,0}, {-s,0,c,0}, {0,0,0,1} };
memcpy(m, &temp, sizeof(Mat));
}

void rotateZ(Mat* m, float t) {
float c = cosf(t), s = sinf(t);
Mat temp = { {c,-s,0,0}, {s,c,0,0}, {0,0,1,0}, {0,0,0,1} };
memcpy(m, &temp, sizeof(Mat));
}

void translate(Mat* m, float x, float y, float z) {
Mat temp = { {1,0,0,x}, {0,1,0,y}, {0,0,1,z}, {0,0,0,1} };
memcpy(m, &temp, sizeof(Mat));
}

void mul(Mat* m, Mat a, Mat b) {
Mat temp;
for (int j = 0; j < 4; j++)
for (int i = 0; i < 4; i++) {
temp[j][i] = 0.0f;
for (int k = 0; k < 4; k++)
temp[j][i] += a[j][k] * b[k][i];
}
memcpy(m, &temp, sizeof(Mat));
}

void transformPosition(Vec* r, Mat m, Vec v) {
Vec temp = { 0, 0, 0, 0 };
for (int j = 0; j < 4; j++)
for (int i = 0; i < 4; i++)
temp[j] += m[j][i] * v[i];
memcpy(r, &temp, sizeof(Vec));
}

float transformLength(Mat m, float r) {
return sqrtf(m[0][0] * m[0][0] + m[0][1] * m[0][1] + m[0][2] * m[0][2]) * r;
}

float sphere(Vec c, float r) {
float dx = c[0] - sx, dy = c[1] - sy;
float a = dx * dx + dy * dy;
return a < r * r ? sqrtf(r * r - a) + c[2] : -1.0f;
}

float opUnion(float z1, float z2) {
return z1 > z2 ? z1 : z2;
}

float f(Mat m, int n) {
float z = -1.0f;
for (float r = 0.0f; r < 0.8f; r += 0.02f) {
Vec v = { 0.0f, r, 0.0f, 1.0f };
transformPosition(&v, m, v);
z = opUnion(z, sphere(v, transformLength(m, 0.05f * (0.95f - r))));
}

if (n > 0) {
Mat ry, rz, s, t, m2, m3;
rotateZ(&rz, 1.8f);

for (int p = 0; p < 6; p++) {
rotateY(&ry, p * (2 * PI / 6));
mul(&m2, ry, rz);
float ss = 0.45f;
for (float r = 0.2f; r < 0.8f; r += 0.1f) {
scale(&s, ss);
translate(&t, 0.0f, r, 0.0f);
mul(&m3, s, m2);
mul(&m3, t, m3);
mul(&m3, m, m3);
z = opUnion(z, f(m3, n - 1));
ss *= 0.8f;
}
}
}

return z;
}

float f0(float x, float y, int n) {
sx = x;
sy = y;
Mat m;
scale(&m, 1.0f);
return f(m, n);
}

int main(int argc, char* argv[]) {
int n = argc > 1 ? atoi(argv[1]) : 3;
float zoom = argc > 2 ? atof(argv[2]) : 1.0f;
for (float y = 0.8f; y > -0.0f; y -= 0.02f / zoom, putchar(‘\n‘))
for (float x = -0.35f; x < 0.35f; x += 0.01f / zoom) {
float z = f0(x, y, n);
if (z > -1.0f) {
float nz = 0.001f;
float nx = f0(x + nz, y, n) - z;
float ny = f0(x, y + nz, n) - z;
float nd = sqrtf(nx * nx + ny * ny + nz * nz);
float d = (nx - ny + nz) / sqrtf(3) / nd;
d = d > 0.0f ? d : 0.0f;
d = d < 1.0f ? d : 1.0f;
putchar(".-:=+*#%@@"[(int)(d * 9.0f)]);
}else
putchar(‘ ‘);
}
}

*********************************************************************************************

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