Dynamic Matrix in C

main.c

/*
 * Copyright 2014 Vincenzo De Notaris
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#include "matrix.h"

int main (int argc, const char * argv[])
{
    matrix m;
    allocate(&m, 1, 1);
    
    addrow(&m);
    for (int c = 0; c < matches.ncols; c++)
        *element(&m, m.nrows - 1, c) = 0;
    
    addcol(&m);
    for (int r = 0; r < m.nrows; r++)
        *element(&m, r, m.ncols - 1) = 0;

}

matrix.c

/*
 * Copyright 2014 Vincenzo De Notaris
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#include "matrix.h"

/* Funzione per l'allocazione in memoria di una matrice di interi */
matrix* allocate(matrix *mat, int nrows, int ncols)
{
    assert(nrows > 0 && ncols > 0);
    mat->nrows = nrows;
    mat->ncols = ncols;
    mat->data = malloc(sizeof(int) * nrows * ncols);
    return mat;
}

/* Funzione per l'accesso (R/W) ad un elemento di una matrice di interi */
int *element(const matrix *mat, int row, int col)
{
    assert(row >= 0 && row < mat->nrows);
    assert(col >= 0 && col < mat->ncols);
    return mat->data + row * mat->ncols + col;
}

/* Funzione per aggiungere una riga in una matrice di interi */
matrix *addrow(matrix *mat)
{
    mat->nrows++;
    mat->data = realloc(mat->data, sizeof(int) * mat->nrows * mat->ncols);
    return mat;
}

/* Funzione per aggiungere una colonna in una matrice di interi */
matrix *addcol(matrix *mat)
{
    mat->ncols++;
    mat->data = realloc(mat->data, sizeof(int) * mat->nrows * mat->ncols);
    
    // Shift degli elementi delle righe
    for (int i = mat->nrows - 1; i > 0; i--)
    {
        int *dest = mat->data + i * mat->ncols,
        *orig = mat->data + i * (mat->ncols - 1);
        memmove(dest, orig, sizeof(int) * (mat->ncols - 1));
    }
    return mat;
}

matrix.h

/*
 * Copyright 2014 Vincenzo De Notaris
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ConnectedComponents_matrix_h
#define ConnectedComponents_matrix_h

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

/* Definizione del tipo matrix e delle struct per modellare una matrice dinamica di interi */
typedef struct matrix {
    int nrows, ncols, *data;
}
matrix; // Nomenclatura associata al tipo definito

/* Funzione per l'allocazione in memoria di una matrice di interi */
matrix* allocate(matrix *mat, int nrows, int ncols);
/* Funzione per l'accesso (R/W) ad un elemento di una matrice di interi */
int *element(const matrix *mat, int row, int col);
/* Funzione per aggiungere una riga in una matrice di interi */
matrix *addrow(matrix *mat);
/* Funzione per aggiungere una colonna in una matrice di interi */
matrix *addcol(matrix *mat);

#endif