no_test/bm.hpp

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• Last update: 2026-05-10 00:56:46+09:00
• Include: #include "no_test/bm.hpp"

Code

template <typename mint>
vector<mint> BerlekampMassey(const vector<mint> &s) {
    const int N = (int)s.size();
    vector<mint> b, c;
    b.reserve(N + 1);
    c.reserve(N + 1);
    b.push_back(mint(1));
    c.push_back(mint(1));
    mint y = mint(1);
    for (int ed = 1; ed <= N; ed++) {
        int l = int(c.size()), m = int(b.size());
        mint x = 0;
        for (int i = 0; i < l; i++) x += c[i] * s[ed - l + i];
        b.emplace_back(mint(0));
        m++;
        if (x == mint(0)) continue;
        mint freq = x / y;
        if (l < m) {
            auto tmp = c;
            c.insert(begin(c), m - l, mint(0));
            for (int i = 0; i < m; i++) c[m - 1 - i] -= freq * b[m - 1 - i];
            b = tmp;
            y = x;
        } else {
            for (int i = 0; i < m; i++) c[l - 1 - i] -= freq * b[m - 1 - i];
        }
    }
    reverse(begin(c), end(c));
    return c;
}

#line 1 "no_test/bm.hpp"
template <typename mint>
vector<mint> BerlekampMassey(const vector<mint> &s) {
    const int N = (int)s.size();
    vector<mint> b, c;
    b.reserve(N + 1);
    c.reserve(N + 1);
    b.push_back(mint(1));
    c.push_back(mint(1));
    mint y = mint(1);
    for (int ed = 1; ed <= N; ed++) {
        int l = int(c.size()), m = int(b.size());
        mint x = 0;
        for (int i = 0; i < l; i++) x += c[i] * s[ed - l + i];
        b.emplace_back(mint(0));
        m++;
        if (x == mint(0)) continue;
        mint freq = x / y;
        if (l < m) {
            auto tmp = c;
            c.insert(begin(c), m - l, mint(0));
            for (int i = 0; i < m; i++) c[m - 1 - i] -= freq * b[m - 1 - i];
            b = tmp;
            y = x;
        } else {
            for (int i = 0; i < m; i++) c[l - 1 - i] -= freq * b[m - 1 - i];
        }
    }
    reverse(begin(c), end(c));
    return c;
}

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