import torch

def compute_accuracy(pad_outputs, pad_targets, ignore_label):
    """Calculate accuracy.

    Args:
        pad_outputs (LongTensor): Prediction tensors (B, Lmax).
        pad_targets (LongTensor): Target label tensors (B, Lmax).
        ignore_label (int): Ignore label id.

    Returns:
        float: Accuracy value (0.0 - 1.0).

    """
    mask = pad_targets != ignore_label
    numerator = torch.sum(
        pad_outputs.masked_select(mask) == pad_targets.masked_select(mask)
    )
    denominator = torch.sum(mask)
    return numerator.float() / denominator.float() #(FIX:MZY):return torch.Tensor type