"""
Utility functions for the Calabi-Yau period geometry project.
"""

def _multi_indices(no_variables, total_degree: int) -> list:
    # All no_variables-tuples of non-negative integers whose entries sum to at most total_degree.
    def helper(remaining_vars, remaining_degree):
        if remaining_vars == 0:
            yield ()
            return
        for first in range(remaining_degree + 1):
            for rest in helper(remaining_vars - 1, remaining_degree - first):
                yield (first,) + rest

    return list(helper(no_variables, total_degree))