#ifndef INCLUDED_C_NONRECURSIVEDIRECTEDDFS_H
#define INCLUDED_C_NONRECURSIVEDIRECTEDDFS_H

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


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

typedef struct {
    c_bool_t*      marked;      /* Visited tracking array (size of graph->V) */
    c_size_t       count;       /* Total number of vertices reachable from source(s) */
    c_Allocator_t  allocator;   /* Copied allocator from the graph for isolation */
} c_NonrecursiveDirectedDFS_t;

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

/**
 * @brief Computes vertices reachable from a single source vertex 's' using a stack
 */
c_err_t c_NonrecursiveDirectedDFS_Init(c_NonrecursiveDirectedDFS_t* self, c_Digraph_t* graph, c_size_t s, c_Allocator_t* allocator);

/**
 * @brief Releases internal tracking buffers
 */
void c_NonrecursiveDirectedDFS_Destroy(c_NonrecursiveDirectedDFS_t* self);

/* ================================================================================================================== */
/* Inline Query Interfaces */

C_STATIC_FORCE_INLINE c_bool_t c_NonrecursiveDirectedDFS_HasPathTo(c_NonrecursiveDirectedDFS_t* self, c_size_t v, c_size_t total_V) {
    if (!self || !self->marked || v >= total_V) return C_FALSE;
    return self->marked[v];
}

C_STATIC_FORCE_INLINE c_size_t c_NonrecursiveDirectedDFS_GetCount(c_NonrecursiveDirectedDFS_t* self) {
    return self ? self->count : 0;
}

#endif /*INCLUDED_C_NONRECURSIVEDIRECTEDDFS_H*/