#ifndef CTC_BEAM_SEARCH_DECODER_H_
#define CTC_BEAM_SEARCH_DECODER_H_

#include <vector>
#include <string>
#include <utility>
#include "scorer.h"

/* CTC Beam Search Decoder, the interface is consistent with the
 * original decoder in Python version.

 * Parameters:
 *     probs_seq: 2-D vector that each element is a vector of probabilities
 *               over vocabulary of one time step.
 *     beam_size: The width of beam search.
 *     vocabulary: A vector of vocabulary.
 *     blank_id: ID of blank.
 *     cutoff_prob: Cutoff probability of pruning
 *     ext_scorer: External scorer to evaluate a prefix.
 *     nproc: Whether this function used in multiprocessing.
 * Return:
 *     A vector that each element is a pair of score  and decoding result,
 *     in desending order.
*/
std::vector<std::pair<double, std::string> >
    ctc_beam_search_decoder(std::vector<std::vector<double> > probs_seq,
                            int beam_size,
                            std::vector<std::string> vocabulary,
                            int blank_id,
                            double cutoff_prob=1.0,
                            Scorer *ext_scorer=NULL,
                            bool nproc=false
                            );

#endif // CTC_BEAM_SEARCH_DECODER_H_