c - 如何在 c 中创建一个用于动态分配二维数组的函数？

Question

#include<stdio.h>
#include<stdlib.h>
void aloc_dinamic(double **M)
{
    int i;
    M = (double **)malloc(m*sizeof(double *));
        for(i=0;i<m;i++)
             M[i] = (double *)calloc(m, sizeof(double));
}
int main(void)
{
    double **H;
    aloc_dinamic(H)
}

如何在 C 中创建一个用于动态分配二维数组的函数？

我试过了，但没用。

Answer 1

#include <stdlib.h>

double ** aloc_dynamic( size_t n, size_t m )
{
    double **p = ( double ** )malloc( n * sizeof( double * ) );

    for ( size_t i = 0; i < n; i++ )
    {
        p[i] = ( double * )malloc( m * sizeof( double ) );
    }

    return p;
}

int main(void)
{
    size_t n = 5;
    size_t m = 10;

    double **p = aloc_dynamic( n, m );

    // before exiting the function free the allocated memory
}