fps/fps_sparsity_detector.hpp

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• Last update: 2025-04-24 20:44:35+09:00
• Include: #include "fps/fps_sparsity_detector.hpp"

Depends on

• bit/bitcount.hpp
• type_traits/integral.hpp

Required by

• convolution/convolution.hpp
• convolution/convolution_arb.hpp
• convolution/convolution_int.hpp
• convolution/multi_convolution_truncated.hpp
• fps/fps_arb.hpp
• fps/fps_multivariate.hpp
• fps/fps_ntt_friendly.hpp
• math_mod/comb_large.hpp

Verified with

• verify/unit_test/large_fact_arb_mod.test.cpp
• verify/yosupo_convolution/convolution_arbitrary.test.cpp
• verify/yosupo_convolution/convolution_multi_truncated.test.cpp
• verify/yosupo_convolution/convolution_ntt_friendly.test.cpp
• verify/yosupo_fps/fps_composition.test.cpp
• verify/yosupo_fps/fps_composition_inv.test.cpp
• verify/yosupo_fps/fps_exp.test.cpp
• verify/yosupo_fps/fps_exp_arb.test.cpp
• verify/yosupo_fps/fps_inv.test.cpp
• verify/yosupo_fps/fps_inv_arb.test.cpp
• verify/yosupo_fps/fps_log.test.cpp
• verify/yosupo_fps/fps_log_arb.test.cpp
• verify/yosupo_fps/fps_multipoint_evaluation.test.cpp
• verify/yosupo_fps/fps_multipoint_evaluation_geometric.test.cpp
• verify/yosupo_fps/fps_pow.test.cpp
• verify/yosupo_fps/fps_product_of_polynomial_sequence.test.cpp
• verify/yosupo_fps/fps_sparse_exp.test.cpp
• verify/yosupo_fps/fps_sparse_inv.test.cpp
• verify/yosupo_fps/fps_sparse_log.test.cpp
• verify/yosupo_fps/fps_sparse_pow.test.cpp
• verify/yosupo_fps/fps_sprase_sqrt.test.cpp
• verify/yosupo_fps/fps_sqrt.test.cpp
• verify/yosupo_fps/poly_division.test.cpp
• verify/yosupo_fps/poly_interpolation.test.cpp
• verify/yosupo_fps/poly_interpolation_geometric.test.cpp
• verify/yosupo_fps/poly_inv.test.cpp
• verify/yosupo_fps/poly_root_finding.test.cpp
• verify/yosupo_fps/poly_sample_point_shift.test.cpp
• verify/yosupo_fps/poly_taylor_shift.test.cpp
• verify/yosupo_fps/poly_to_newton_basis.test.cpp
• verify/yosupo_math/enumerate_bell_number.test.cpp
• verify/yosupo_math/enumerate_stirling_number_of_the_first_kind.test.cpp
• verify/yosupo_math/kth_term_of_linearly_recurrent_sequence.test.cpp
• verify/yosupo_math/many_factrials.test.cpp
• verify/yuki/yuki_1510.test.cpp

Code

#ifndef KK2_FPS_FPS_SPARSITY_DETECTOR_HPP
#define KK2_FPS_FPS_SPARSITY_DETECTOR_HPP 1

#include "../bit/bitcount.hpp"

namespace kk2 {

enum class FPSOperation { CONVOLUTION };

template <class FPS, class mint = typename FPS::value_type>
bool is_sparse_operation(FPSOperation op, bool is_ntt_friendly, const FPS &a, const FPS &b) {
    int n = a.size(), m = b.size();
    long long not_zero_a = 0, not_zero_b = 0;
    for (int i = 0; i < n; i++) not_zero_a += a[i] != mint(0);
    for (int i = 0; i < m; i++) not_zero_b += b[i] != mint(0);

    if (op == FPSOperation::CONVOLUTION) {
        // NTT-friendly -> 3 * FFT
        // Arbitrary    -> 9 * FFT
        // Sparse       -> not_zero(a) * not_zero(b)
        int lg = msb(n + m) / 2 + 1;
        return (n + m) * lg * (is_ntt_friendly ? 3 : 7) > not_zero_a * not_zero_b;
    }
    return false;
}

} // namespace kk2

#endif // KK2_FPS_FPS_SPARSITY_DETECTOR_HPP

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/onlinejudge_verify/documentation/build.py", line 71, in _render_source_code_stat
    bundled_code = language.bundle(stat.path, basedir=basedir, options={'include_paths': [basedir]}).decode()
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/onlinejudge_verify/languages/cplusplus.py", line 187, in bundle
    bundler.update(path)
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/onlinejudge_verify/languages/cplusplus_bundle.py", line 401, in update
    self.update(self._resolve(pathlib.Path(included), included_from=path))
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/onlinejudge_verify/languages/cplusplus_bundle.py", line 401, in update
    self.update(self._resolve(pathlib.Path(included), included_from=path))
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/onlinejudge_verify/languages/cplusplus_bundle.py", line 312, in update
    raise BundleErrorAt(path, i + 1, "#pragma once found in a non-first line")
onlinejudge_verify.languages.cplusplus_bundle.BundleErrorAt: type_traits/integral.hpp: line 4: #pragma once found in a non-first line

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