c - 声明两个大型二维数组会导致段错误

Question

我正在尝试为两个二维数组声明和分配内存。然而，当尝试为 itemFeatureQ[39][16816] 分配值时，我得到了一个分段库。我无法理解它，因为我有 2GB RAM，但堆上只使用了 19MB。这是代码；

double** reserveMemory(int rows, int columns)
{
    double **array;
    int i;
    array = (double**) malloc(rows * sizeof(double *));
    if(array == NULL)
    {
        fprintf(stderr, "out of memory\n");
        return NULL;
    }
    for(i = 0; i < rows; i++)
    {
        array[i] = (double*) malloc(columns * sizeof(double *));
        if(array == NULL)
        {
            fprintf(stderr, "out of memory\n");
            return NULL;
        }
    }

    return array;

}

void populateUserFeatureP(double **userFeatureP)
{
    int x,y;

    for(x = 0; x < CUSTOMERS; x++)
    {
        for(y = 0; y < FEATURES; y++)
        {
            userFeatureP[x][y] = 0;
        }
    }
}

void populateItemFeatureQ(double **itemFeatureQ)
{
    int x,y;

    for(x = 0; x < FEATURES; x++)
    {
        for(y = 0; y < MOVIES; y++)
        {
            printf("(%d,%d)\n", x, y);
            itemFeatureQ[x][y] = 0;
        }
    }
}

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

    double **userFeatureP = reserveMemory(480189, 40);
    double **itemFeatureQ = reserveMemory(40, 17770);

    populateItemFeatureQ(itemFeatureQ);
    populateUserFeatureP(userFeatureP);

    return 0;
}

Answer 1

您有几个拼写错误 - 更改:

    array[i] = (double*) malloc(columns * sizeof(double *));
    if(array == NULL)

至:

    array[i] = (double*) malloc(columns * sizeof(double));
    if(array[i] == NULL)