#ifndef INCLUDED_C_DEPTHFIRSTORDER_H
#define INCLUDED_C_DEPTHFIRSTORDER_H

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


#ifndef INCLUDED_C_VERTEXIDLIST_H
#include <c_VertexIdList.h>
#endif /*INCLUDED_C_VERTEXIDLIST_H*/


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

typedef struct {
    c_bool_t*          marked;          /* Visited tracking array (size of graph->V) */
    c_VertexIdList_t   pre_order;       /* Vertices in pre-order sequence */
    c_VertexIdList_t   post_order;      /* Vertices in post-order sequence */
    c_VertexIdList_t   reverse_post;    /* Vertices in reverse post-order sequence */
    c_Allocator_t      allocator;       /* Deep copy of the user-provided allocator */
} c_DepthFirstOrder_t;

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

/**
 * @brief Computes pre-order, post-order, and reverse post-order traversals for a digraph.
 * @param allocator Explicit allocator context used to allocate internal arrays and lists
 */
c_err_t c_DepthFirstOrder_Init(c_DepthFirstOrder_t* self, c_Digraph_t* graph, c_Allocator_t* allocator);

/**
 * @brief Releases internal tracking buffers
 */
void c_DepthFirstOrder_Destroy(c_DepthFirstOrder_t* self);

/**
 * @brief Gets a copy of the pre-order vertex list.
 */
c_err_t c_DepthFirstOrder_GetPre(c_DepthFirstOrder_t* self, c_VertexIdList_t* out_list);

/**
 * @brief Gets a copy of the post-order vertex list.
 */
c_err_t c_DepthFirstOrder_GetPost(c_DepthFirstOrder_t* self, c_VertexIdList_t* out_list);

/**
 * @brief Gets a copy of the reverse post-order vertex list (Topological order candidate).
 */
c_err_t c_DepthFirstOrder_GetReversePost(c_DepthFirstOrder_t* self, c_VertexIdList_t* out_list);


#endif /*INCLUDED_C_DEPTHFIRSTORDER_H*/