长度较短的模板代码（持续更新

浮点数高斯消元

int cur = 0;
for (int i = 0; i < n; ++i) {
  int p = cur;
  for (int j = cur + 1; j < n; ++j)
    if (abs(M[j][i]) > abs(M[p][i]))
      p = j;
  if (abs(M[p][i]) < EPS)
    continue;
  if (p != cur)
    for (int j = i; j <= n; ++j)
      swap(M[p][j], M[cur][j]);
  for (int j = n; j >= i; --j)
    M[cur][j] /= M[cur][i];
  for (int j = 0; j < n; ++j)
    if (j != cur)
      for (int k = n; k >= i; --k)
        M[j][k] -= M[j][i] * M[cur][k];
  ++cur;
}
if (cur < n) {
  for (int i = cur; i < n; ++i)
    if (abs(M[i][n]) > EPS)
      return cout << -1 << '\n', 0;
  return cout << 0 << '\n', 0;
}
for (int i = 0; i < n; ++i)
  cout << "x" << i + 1 << "=" << M[i][n] << '\n';

线性基

struct basis {
  uint64_t p[64];
  basis() { memset(p, 0, sizeof(p)); }
  void insert(uint64_t x) {
    for (size_t i = 63; ~i; --i) {
      if (!(x >> i))
        continue;
      if (!p[i]) {
        p[i] = x;
        break;
      }
      x ^= p[i];
    }
  }
  uint64_t query_max(uint64_t x = 0) {
    uint64_t res = x;
    for (size_t i = 63; ~i; --i)
      res = max(res, res ^ p[i]);
    return res;
  }
};