#ifndef INCLUDED_C_INDEXMINPQ_H
#define INCLUDED_C_INDEXMINPQ_H

#ifndef INCLUDED_C_TYPES_H
#include <c_Types.h>
#endif /*INCLUDED_C_TYPES_H*/

#ifndef INCLUDED_C_SORTCOMPARE_H
#include <c_SortCompare.h>
#endif /*INCLUDED_C_SORTCOMPARE_H*/

#ifndef INCLUDED_C_ALLOCATOR_H
#include <c_Allocator.h>
#endif /*INCLUDED_C_ALLOCATOR_H*/




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

typedef struct {
    c_size_t max_elements;   // 迭代器或外部图允许的最大唯一索引上限 (Index Max Limit)
    c_size_t size;           // 当前优先队列内有效驻留的索引总个数
    c_size_t elem_size;      // 单个关联数据元素占用的物理字节大小 (sizeof)

    c_size_t* pq;            // 物理堆数组：pq[i] 代表处于堆物理位置 i 处的用户唯一索引 (index)
    c_size_t* qp;            // 逆向映射映射表：qp[index] 代表用户唯一索引在堆数组中的物理物理下标位置 (Heap Position)
    // 特殊约束：若某个索引未入队，其 qp[index] 的值恒被安全填充为 (c_size_t)-1

    char* keys;              // 密集关联数据存储块：keys[index * elem_size] 存储该索引对应的真实优先级数据

    c_SortCompare_t cmp;     // 动态比对器
    void* args;              // 自定义上下文
    c_Allocator_t allocator; // 组合分配器实体，实现自适应Fallback缺省
} c_IndexMinPQ_t;

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

c_err_t c_IndexMinPQ_Init(c_IndexMinPQ_t* self, c_size_t max_elements, c_size_t elem_size, c_SortCompare_t cmp, void* args, c_Allocator_t* allocator);

bool c_IndexMinPQ_Contains(const c_IndexMinPQ_t* pq, c_size_t index);

c_err_t c_IndexMinPQ_Push(c_IndexMinPQ_t* pq, c_size_t index, const void* item);

c_err_t c_IndexMinPQ_Pop(c_IndexMinPQ_t* pq, c_size_t* out_index);

c_err_t c_IndexMinPQ_Change(c_IndexMinPQ_t* pq, c_size_t index, const void* new_item);

c_err_t c_IndexMinPQ_Peek(const c_IndexMinPQ_t* pq, c_size_t* out_index);

void c_IndexMinPQ_Destroy(c_IndexMinPQ_t* pq);

#endif /*INCLUDED_C_INDEXMINPQ_H*/