// Catalan Number
//
// catalan - C(n)
//
// nth Catalan number: C(n) = (2n)! / ((n+1)! * n!)
//
// Inputs:    1 (n)
// Outputs:   1 (Catalan number)
// Constants: 0

#include <math.h>
#include "ts.h"



ts_parameter_t const ts_catalan_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };


uint_t ts_catalan_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 0 );
}

int ts_catalan(
	fp_t * const *y, uint_t y_n,
	fp_t const * const *x, uint_t x_n,
	uint_t n, ts_constant_t const *c
)
{
	TS_PROLOGUE( ts_catalan_p );
	(void)c;
	for( uint_t i = 0; i < n; ++i )
	{
		fp_t xv = x[0][i];
		if (isnan(xv) || isinf(xv) || xv < 0 || xv != (fp_t)(uint_t)xv) {
			y[0][i] = 0;
			continue;
		}
		uint_t n_val = (uint_t)xv;
		fp_t result = 1.0;
		for( uint_t j = 0; j < n_val; ++j )
		{
			result *= (fp_t)(j + n_val + 1);
			result /= (fp_t)(j + 1);
		}
		result /= (fp_t)(n_val + 1);
		y[0][i] = result;
	}
	return 0;
}