#ifndef INCLUDED_C_QUICKFINDUF_H
#define INCLUDED_C_QUICKFINDUF_H

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

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


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

typedef struct {
    c_size_t* id;
    c_size_t n;
    c_size_t count;
    c_Allocator_t allocator;
}c_QuickFindUF_t;

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

C_STATIC_FORCE_INLINE
c_err_t c_QuickFindUF_Init(c_QuickFindUF_t* self, c_size_t n, c_Allocator_t* allocator) {
    if (!self) return C_ERR_PARAM;
    self->allocator = allocator?*allocator:c_DefaultAllocator;
    self->n = n;
    self->id = c_Allocator_Alloc(&self->allocator, n * sizeof(*self->id));
    if (!self->id) return C_ERR_NOMEM;
    self->count = n;
    for (c_size_t i=0; i<n; i++) {
        self->id[i] = i;
    }
    return C_ERR_OK;
}

C_STATIC_FORCE_INLINE
void c_QuickFindUF_Destroy(c_QuickFindUF_t* self) {
    if (!self) return;
    if (self->id) {
        c_Allocator_Free(&self->allocator, self->id);
        self->id = NULL;
    }
    self->n = 0;
    self->count = 0;
}

C_STATIC_FORCE_INLINE
c_err_t c_QuickFindUF_Find(c_QuickFindUF_t* self, c_size_t p, c_size_t* out) {
    if (!self) return C_ERR_PARAM;
    if (p >= self->n) return C_ERR_OUTOFBOUND;
    if (out) {
        *out = self->id[p];
    }
    return C_ERR_OK;
}

C_STATIC_FORCE_INLINE
c_err_t c_QuickFindUF_Union(c_QuickFindUF_t* self, c_size_t p, c_size_t q) {
    if (!self) return C_ERR_PARAM;
    if (p >= self->n || q>=self->n) return C_ERR_OUTOFBOUND;
    c_size_t pID = self->id[p];
    c_size_t qID = self->id[q];
    if (pID == qID) return C_ERR_OK;
    for (c_size_t i=0; i<self->n; i++) {
        if (self->id[i] == pID) {
            self->id[i] = qID;
        }
    }
    self->count--;
    return C_ERR_OK;
}

C_STATIC_FORCE_INLINE
bool c_QuickFindUF_IsConnected(c_QuickFindUF_t* self, c_size_t p, c_size_t q) {
    if (!self) return false;
    if (p >= self->n || q>=self->n) return false;
    return self->id[p] == self->id[q];
}

#endif /*INCLUDED_C_QUICKFINDUF_H*/