int main() { slong iter; flint_rand_t state; flint_printf("fac2_ui...."); fflush(stdout); flint_randinit(state); for (iter = 0; iter < 1000; iter++) { arb_t a, b, c; ulong n; slong prec1, prec2; prec1 = 2 + n_randint(state, 300); prec2 = 2 + n_randint(state, 300); arb_init(a); arb_init(b); arb_init(c); n = n_randtest(state); if (n + 1 == 0 || n + 2 == 0) n -= 2; arb_fac2_ui(a, n, prec1); arb_fac2_ui(b, n + 2, prec1); arb_mul_ui(c, a, n + 2, prec2); if (!arb_overlaps(b, c)) { flint_printf("FAIL: overlap\n\n"); flint_printf("a = "); arb_print(a); flint_printf("\n\n"); flint_printf("b = "); arb_print(b); flint_printf("\n\n"); flint_printf("c = "); arb_print(c); flint_printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); } flint_randclear(state); flint_cleanup(); flint_printf("PASS\n"); return EXIT_SUCCESS; }
void arb_fac2_ui(arb_t res, ulong n, long prec) { if (n % 2 == 0) { arb_fac_ui(res, n / 2, prec); arb_mul_2exp_si(res, res, n / 2); } else { arb_t t; arb_init(t); arb_fac2_ui(t, n - 1, prec + 5); arb_fac_ui(res, n, prec + 5); arb_div(res, res, t, prec); arb_clear(t); } }