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/*

Exhaustive search of xorshift parameters

Copyright 2025 Ahmet Inan <inan@aicodix.de>

*/

#include <stdio.h>

#include <stdlib.h>

int main(int argc, char **argv) {

if (argc != 2)

return 1;

int bits = atoi(argv[1]);

int mask = (1 << bits) - 1;

int seed = 1;

for (int a = 1; a < bits; ++a) {

for (int b = 1; b < bits; ++b) {

for (int c = 1; c < bits; ++c) {

int good = 1;

for (int y = seed, i = mask; good && i; --i) {

y ^= y << a;

y &= mask;

y ^= y >> b;

y ^= y << c;

y &= mask;

good &= (i == 1) == (y == seed);

}

if (good)

printf("%d %d %d\\n", a, b, c);

}

}

}

return 0;

}