Vettori Dinamici in C

Programmazione » Vettori dinamici c
28/05/2017 - 514

I vettori dinamici in C come nel C++ tramite una libreria

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Vettori dinamici in C come nel C++

Tra le varie caratteristiche del C++ vi è il supporto per i vettori dinamici tramite la libreria STD e il template class vector, rispetto gli array tradizionali è possibile modificare dinamicamente la dimensione dei vettori, aggiungere e rimuovere elementi queste funzionalità sono sicuramente molto apprezzate dai programmatori.

In C purtroppo non vi è nessuna libreria standard per gestire array dinamici, in questo articolo vedremo un esempio di una libreria che emula la classe template vector del c++.

int main(int argc, char** argv) {

    int i = 0;

    VectorGeneric_DataType theVector;

    VectorGeneric_Init(&theVector);

    for (i = 0; i < 10; i++)

    {

        theVector.PushBack((void *)&theVector, (void *) &i, sizeof(int));

    }

    printf("\n\nVector Content");

    for (i = 0; i < theVector.size; i++)

    {

       printf("\n Element[%d] = %d", i, *(int *)theVector.data[i]);

    }

    theVector.DeleteAt(&theVector, 7, free);

    printf("\n\nVector Content After deleting item at position 7");

    for (i = 0; i < theVector.size; i++)

    {

       printf("\n Element[%d] = %d", i, *(int *)theVector.data[i]);

    }

return (EXIT_SUCCESS);

}

Output del codice qui sopra:

Vector Content

 Element[0] = 0

 Element[1] = 1

 Element[2] = 2

 Element[3] = 3

 Element[4] = 4

 Element[5] = 5

 Element[6] = 6

 Element[7] = 7

 Element[8] = 8

 Element[9] = 9



Vector Content After deleting item at position 7

 Element[0] = 0

 Element[1] = 1

 Element[2] = 2

 Element[3] = 3

 Element[4] = 4

 Element[5] = 5

 Element[6] = 6

 Element[7] = 8

 Element[8] = 9

File "cvector.c"

#include 

#include 

#include 

#include "cvectors.h"



void VectorGeneric_Init(VectorGeneric_DataType *TheVectorGeneric)

{

    TheVectorGeneric->size = 0;

    TheVectorGeneric->data = NULL;

    TheVectorGeneric->element_size = NULL;

    //Functions Pointers

    TheVectorGeneric->DeleteAt = (void *)VectorGeneric_DeleteAt;

    TheVectorGeneric->Destroy = (void *)VectorGeneric_Destroy;

    TheVectorGeneric->PopBack = (void *)VectorGeneric_PopBack;

    TheVectorGeneric->PushBack = (void *)VectorGeneric_PushBack;

    TheVectorGeneric->SoftDestroy = (void *)VectorGeneric_SoftDestroy;

    TheVectorGeneric->SoftPopBack = (void *)VectorGeneric_SoftPopBack;

}



void VectorGeneric_PushBack(VectorGeneric_DataType *TheVectorGeneric, void * TheElementData, int TheElementSize)

{

    if (TheVectorGeneric->data != NULL)

    {

        TheVectorGeneric->data = (void **) realloc(TheVectorGeneric->data, sizeof(void *) * (TheVectorGeneric->size+1));

    }

    else

    {

        TheVectorGeneric->data = (void **) malloc (sizeof(void *) * (TheVectorGeneric->size+1));

    }

    if (TheVectorGeneric->element_size != NULL)

    {

        TheVectorGeneric->element_size = (int *) realloc (TheVectorGeneric->element_size, sizeof(int) * (TheVectorGeneric->size+1));

    }

    else

    {

        TheVectorGeneric->element_size = (int *) malloc (sizeof(int));

    }

    TheVectorGeneric->data[TheVectorGeneric->size] = (void *) calloc(1, TheElementSize);

    memcpy(TheVectorGeneric->data[TheVectorGeneric->size], TheElementData, TheElementSize);

    TheVectorGeneric->element_size[TheVectorGeneric->size] = TheElementSize;

    TheVectorGeneric->size++;

}



void VectorGeneric_PopBack(VectorGeneric_DataType *TheVector, void (*DeleteElementFunction)(void *TheElementToDelete))

{

    DeleteElementFunction((void *) TheVector->data[TheVector->size-1]);

    free(TheVector->data[TheVector->size-1]);

    if (TheVector->size > 1)

    {

        TheVector->data = (void **) realloc(TheVector->data, sizeof(void *) * (TheVector->size-1));

        TheVector->element_size = (int *) realloc (TheVector->element_size, sizeof(int) * (TheVector->size-1));

    }

    else

    {

        free(TheVector->data);

        free(TheVector->element_size);

        TheVector->data = NULL;

        TheVector->element_size = NULL;

    }

    TheVector->size--;

}



void VectorGeneric_SoftPopBack(VectorGeneric_DataType *TheVector)

{

    free(TheVector->data[TheVector->size-1]);

    if (TheVector->size > 1)

    {

        TheVector->data = (void **) realloc(TheVector->data, sizeof(void *) * (TheVector->size-1));

        TheVector->element_size = (int *) realloc (TheVector->element_size, sizeof(int) * (TheVector->size-1));

    }

    else

    {

        free(TheVector->data);

        free(TheVector->element_size);

        TheVector->data = NULL;

        TheVector->element_size = NULL;

    }

    TheVector->size--;

}

void VectorGeneric_Destroy(VectorGeneric_DataType *TheVector, void (*DeleteElementFunction)(void *TheElementToDelete))

{

    int i;

    for (i = 0; i < TheVector->size; i++)

    {

    	DeleteElementFunction((void *) TheVector->data[i]);

        free(TheVector->data[i]);

    }

    free(TheVector->data);

    free(TheVector->element_size);

    TheVector->data = NULL;

    TheVector->element_size = NULL;

    TheVector->size = 0;

}

void VectorGeneric_SoftDestroy(VectorGeneric_DataType *TheVector)

{

    int i;

    for (i = 0; i < TheVector->size; i++)

    {

        free(TheVector->data[i]);

    }

    free(TheVector->data);

    free(TheVector->element_size);

    TheVector->data = NULL;

    TheVector->element_size = NULL;

    TheVector->size = 0;

}

void VectorGeneric_DeleteAt(VectorGeneric_DataType *TheVector, int index, void (*DeleteElementFunction)(void *TheElementToDelete))

{

    int i;

    VectorGeneric_DataType TempVector;

    VectorGeneric_Init(&TempVector);

    for (i = index + 1; i < TheVector->size; i++)

    {

    	VectorGeneric_PushBack(&TempVector, TheVector->data[i], TheVector->element_size[i]);

    }

    //Permanent delete of the item in the heap

    DeleteElementFunction((void *) TheVector->data[index]);

    while (TheVector->size > index)

    {

    	VectorGeneric_SoftPopBack(TheVector);

    }

    for (i = 0; i < TempVector.size; i++)

    {

    	VectorGeneric_PushBack(TheVector, TempVector.data[i], TempVector.element_size[i]);

    }

    VectorGeneric_SoftDestroy(&TempVector);

}

void VectorString_Init(VectorString_DataType *TheVector)

{

    TheVector->size = 0;

    TheVector->data = NULL;

    TheVector->element_size = NULL;

    //Functions Pointers

    TheVector->DeleteAt = (void *)VectorString_DeleteAt;

    TheVector->Destroy = (void *)VectorString_Destroy;

    TheVector->PopBack = (void *)VectorString_PopBack;

    TheVector->PushBack = (void *)VectorString_PushBack;

}



void VectorString_PushBack(VectorString_DataType *TheVector, char * TheString, int StringLenght)

{

    int i;

    if (TheVector->data != NULL)

    {

        TheVector->data = (char **)realloc(TheVector->data, sizeof(char *) * (TheVector->size+1));

    }

    else

    {

        TheVector->data = (char **) malloc (sizeof(char *) * (TheVector->size+1));

    }

    if (TheVector->element_size != NULL)

    {

        TheVector->element_size = (int *) realloc (TheVector->element_size, sizeof(int) * (TheVector->size+1));

    }

    else

    {

        TheVector->element_size = (int *) malloc (sizeof(int) * 1);

    }

    TheVector->data[TheVector->size] = (char *) calloc(sizeof(char), StringLenght + 1);

    for (i = 0; i < StringLenght; i++ )

    {

        TheVector->data[TheVector->size][i] = TheString[i];

    }

    TheVector->element_size[TheVector->size] = i;

    TheVector->data[TheVector->size][TheVector->element_size[TheVector->size]] = '\0';

    TheVector->size++;

}



void VectorString_PopBack(VectorString_DataType *TheVector)

{

    free(TheVector->data[TheVector->size-1]);

    if (TheVector->size > 1)

    {

        TheVector->data = (char **)realloc(TheVector->data, sizeof(char *) * (TheVector->size-1));

        TheVector->element_size = (int *) realloc (TheVector->element_size, sizeof(int) * (TheVector->size-1));

    }

    else

    {

        free(TheVector->data);

        free(TheVector->element_size);

        TheVector->data = NULL;

        TheVector->element_size = NULL;

    }

    TheVector->size--;

}



void VectorString_Destroy(VectorString_DataType *TheVector)

{

    int i;

    for (i = 0; i < TheVector->size; i++)

    {

        free(TheVector->data[i]);

    }

    free(TheVector->data);

    free(TheVector->element_size);

    TheVector->data = NULL;

    TheVector->element_size = NULL;

    TheVector->size = 0;

}



void VectorString_DeleteAt(VectorString_DataType *TheVector, int index)

{

    int i;

    VectorString_DataType TempVector;

    VectorString_Init(&TempVector);

    for (i = index + 1; i < TheVector->size; i++)

    {

        VectorString_PushBack(&TempVector, TheVector->data[i], TheVector->element_size[i]);

    }

    while (TheVector->size > index)

    {

        VectorString_PopBack(TheVector);

    }

    for (i = 0; i < TempVector.size; i++)

    {

        VectorString_PushBack(TheVector, TempVector.data[i], TempVector.element_size[i]);

    }

    VectorString_Destroy(&TempVector);

}

File "cvector.h"

#ifndef CVECTORS_H

#define	CVECTORS_H

#ifdef	__cplusplus

extern "C" {

#endif

struct VectorString

{

    char **data;

    int size;

    int *element_size;

    void (*PushBack)(void *TheVector, char * TheString, int StringLenght);

    void (*PopBack)(void *TheVector);

    void (*Destroy)(void *TheVector);

    void (*DeleteAt)(void *TheVector, int index);

} typedef VectorString_DataType;



struct VectorGeneric

{

    void **data;

    int size;

    int *element_size;

    void (*PushBack)(void *TheVectorGeneric, void * TheElementData, int TheElementSize);

    void (*PopBack)(void *TheVector, void (*DeleteElement)(void *TheElementToDelete));

    void (*SoftPopBack)(void *TheVector);

    void (*Destroy)(void *TheVector, void (*DeleteElement)(void *TheElementToDelete));

    void (*SoftDestroy)(void *TheVector);

    void (*DeleteAt)(void *TheVector, int index, void (*DeleteElement)(void *TheElementToDelete));

} typedef VectorGeneric_DataType;



void VectorString_Init(VectorString_DataType *TheVector);

void VectorString_PushBack(VectorString_DataType *TheVector, char * TheString, int StringLenght);

void VectorString_PopBack(VectorString_DataType *TheVector);

void VectorString_Destroy(VectorString_DataType *TheVector);

void VectorString_DeleteAt(VectorString_DataType *TheVector, int index);

void VectorGeneric_Init(VectorGeneric_DataType *TheVectorGeneric);

void VectorGeneric_PushBack(VectorGeneric_DataType *TheVectorGeneric, void * TheElementData, int TheElementSize);

void VectorGeneric_PopBack(VectorGeneric_DataType *TheVector, void (*DeleteElementFunction)(void *TheElementToDelete));

void VectorGeneric_SoftPopBack(VectorGeneric_DataType *TheVector);

void VectorGeneric_Destroy(VectorGeneric_DataType *TheVector, void (*DeleteElementFunction)(void *TheElementToDelete));

void VectorGeneric_SoftDestroy(VectorGeneric_DataType *TheVector);

void VectorGeneric_DeleteAt(VectorGeneric_DataType *TheVector, int index, void (*DeleteElementFunction)(void *TheElementToDelete));

#ifdef	__cplusplus

}

#endif

#endif

/* CVECTORS_H */