zett

#include <stdint.h>
#include <stdio.h>

#define ROTL(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
#define QR(a, b, c, d) (             \
    a += b, d ^= a, d = ROTL(d, 16), \
    c += d, b ^= c, b = ROTL(b, 12), \
    a += b, d ^= a, d = ROTL(d,  8), \
    c += d, b ^= c, b = ROTL(b,  7))
#define ROUNDS 20

void chacha_block(uint32_t out[16], uint32_t const in[16])
{
    int i;
    uint32_t x[16];

    for (i = 0; i < 16; ++i)
        x[i] = in[i];
    // 10 loops × 2 rounds/loop = 20 rounds
    for (i = 0; i < ROUNDS; i += 2) {
        // Odd round
        QR(x[0], x[4], x[ 8], x[12]); // column 1
        QR(x[1], x[5], x[ 9], x[13]); // column 2
        QR(x[2], x[6], x[10], x[14]); // column 3
        QR(x[3], x[7], x[11], x[15]); // column 4
        // Even round
        QR(x[0], x[5], x[10], x[15]); // diagonal 1 (main diagonal)
        QR(x[1], x[6], x[11], x[12]); // diagonal 2
        QR(x[2], x[7], x[ 8], x[13]); // diagonal 3
        QR(x[3], x[4], x[ 9], x[14]); // diagonal 4
    }
    for (i = 0; i < 16; ++i)
        out[i] = x[i] + in[i];
}

void generate_pseudorandom_truths(uint32_t seed, int count, int truths[])
{
    uint32_t input[16] = {
        0x61707865, 0x3320646e, 0x79622d32, 0x6b206574,
        0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c,
        0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
        0x00000001, seed,        0x4a000000, 0x00000000
    };
    uint32_t output[16];
    int i, j;

    for (i = 0; i < count; ++i) {
        chacha_block(output, input);
        for (j = 0; j < 16 && i < count; ++j, ++i) {
            truths[i] = output[j] & 1; // Convert to boolean
        }
    }
}

int main(void)
{
    int count = 16; // Number of truth values to generate
    uint32_t seed = 0x31515433; // Example seed
    int truths[count];
    int i, j;

    for (j = 0; j < 100; ++j) { // Loop n times
        printf("Iteration %d:\n", j+1);
        seed -= 133;
        generate_pseudorandom_truths(seed, count, truths);

        printf("Pseudorandom truth values:\n");
        for (i = 0; i < count; ++i) {
            printf("%d ", truths[i]);
            if ((i & 15) == 15) printf("\n");
        }
    }
    return 0;
}