#ifndef INCLUDED_C_EULERIANCYCLE_H
#define INCLUDED_C_EULERIANCYCLE_H

#ifndef INCLUDED_C_GRAPH_H
#include <c_Graph.h>
#endif /*INCLUDED_C_GRAPH_H*/


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


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

typedef struct {
    c_VertexIdList_t cycle;         // Stores the structural sequence of vertices forming the cycle
    c_bool_t      has_cycle;     // True if an Eulerian cycle exists in the graph
    c_Allocator_t allocator;     // Memory allocator reference instance copy
} c_EulerianCycle_t;

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

/**
 * @brief Computes an Eulerian cycle in an undirected graph if one exists.
 * @param self Pointer to the uninitialized Eulerian cycle tracking structure.
 * @param G Pointer to the constant target graph object to analyze.
 * @param allocator Memory allocator instance pointer to deploy.
 * @return C_SUCCESS on success, or an error status code on allocation failure.
 */
c_err_t c_EulerianCycle_Init(c_EulerianCycle_t* self, const c_Graph_t* G, c_Allocator_t* allocator);

/**
 * @brief Drops all internal allocation states within the Eulerian cycle instance safely.
 */
void     c_EulerianCycle_Destroy(c_EulerianCycle_t* self);

/**
 * @brief Does the graph contain an Eulerian cycle?
 */
c_bool_t c_EulerianCycle_HasCycle(const c_EulerianCycle_t* self);

/**
 * @brief Returns the vertex path sequence forming the Eulerian cycle, or empty if none exists.
 */
const c_VertexIdList_t* c_EulerianCycle_Path(const c_EulerianCycle_t* self);

#endif /*INCLUDED_C_EULERIANCYCLE_H*/