#ifndef INCLUDED_C_TRANSITIVECLOSURE_H
#define INCLUDED_C_TRANSITIVECLOSURE_H

#ifndef INCLUDED_C_DIGRAPH_H
#include <c_Digraph.h>
#endif /*INCLUDED_C_DIGRAPH_H*/

#ifndef INCLUDED_C_NONRECURSIVEDIRECTEDDFS
#include <c_NonrecursiveDirectedDFS.h>
#endif /*INCLUDED_C_NONRECURSIVEDIRECTEDDFS*/


/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

typedef struct {
    c_NonrecursiveDirectedDFS_t*  dfs_matrix;  /* Array of DFS instances (size of graph->V) */
    c_size_t                      V;           /* Stored vertex count for boundary safe checks */
    c_Allocator_t                 allocator;   /* Deep copy of the user-provided allocator */
} c_TransitiveClosure_t;

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

/**
 * @brief Computes the transitive closure of a digraph to support all-pairs reachability queries.
 * @param allocator Explicit allocator context used to allocate internal search objects
 */
c_err_t c_TransitiveClosure_Init(c_TransitiveClosure_t* self, c_Digraph_t* graph, c_Allocator_t* allocator);

/**
 * @brief Releases internal tracking buffers and all embedded search matrices
 */
void c_TransitiveClosure_Destroy(c_TransitiveClosure_t* self);

/**
 * @brief Is vertex 'v' reachable from vertex 'u'?
 * @return C_TRUE if there is a directed path from 'u' to 'v', C_FALSE otherwise
 */
C_STATIC_FORCE_INLINE
c_bool_t c_TransitiveClosure_Reachable(c_TransitiveClosure_t* self, c_size_t u, c_size_t v) {
    if (!self || !self->dfs_matrix || u >= self->V || v >= self->V) return C_FALSE;
    return c_NonrecursiveDirectedDFS_HasPathTo(&self->dfs_matrix[u], v, self->V);
}

#endif /*INCLUDED_C_TRANSITIVECLOSURE_H*/