diff options
Diffstat (limited to 'lib/is_prime.c')
| -rw-r--r-- | lib/is_prime.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/lib/is_prime.c b/lib/is_prime.c new file mode 100644 index 0000000..119c9a4 --- /dev/null +++ b/lib/is_prime.c @@ -0,0 +1,69 @@ +// Is Prime +// +// is_prime +// +// Prime number test +// +// 1 if prime, 0 otherwise +// +// Inputs: 1 +// Outputs: 1 +// Constants: 0 + + +#include <math.h> +#include "ts.h" + + +ts_parameter_t const ts_is_prime_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 }; + +uint_t ts_is_prime_offset( ts_constant_t const *c ) +{ + ( void )c; + return ( 0 ); +} + +int ts_is_prime( + 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_is_prime_p ); + (void)c; + for( uint_t i = 0; i < n; ++i ) + { + fp_t v = x[0][i]; + if (v > 1e15 || v < -1e15) { y[0][i] = 0.0; continue; } + long n_val = (long)v; + if( n_val < 2 ) + { + y[0][i] = 0.0; + continue; + } + if( n_val == 2 ) + { + y[0][i] = 1.0; + continue; + } + if( n_val % 2 == 0 ) + { + y[0][i] = 0.0; + continue; + } + int prime = 1; + for( long d = 3; d <= n_val / d; d += 2 ) + { + if( n_val % d == 0 ) + { + prime = 0; + break; + } + } + y[0][i] = prime ? 1.0 : 0.0; + } + return 0; +} + + + |