返回两个指向动态数组的指针

Question

我在这里遇到了一堆关于指针和动态数组的问题。我有一个我调用的函数，它做了很多事情，比如从动态数组中删除一个元素，这导致我将内存重新分配给其中一个动态数组。问题是我在函数内调用函数，但我无法 return 将所有值正确地传递给 Main。由于我不能 return 2 个值，我该怎么做？

structure1* register(structure1 *registerArray,structure2 *waitingList, int counter){
    //Bunch of code in here
    registerArray = realloc(inspecao, (counter)+1);
    waitingList = eliminate(waitingList, 5, counter); //Doesn't matter what it does really

    return registerArray;
}


structure1* eliminate(structure1 *arrayToEliminateFrom, int positionToEliminate, int *counter){

    //The code for this doesn't matter
    //All I do is eliminate an ellement and reallocate it
    arrayToEliminateFrom = realloc(arrayToEliminateFrom, (*counter-1)*sizeof(structure1))
    return arrayToEliminateFrom;
}

如您所见，我不知道如何将指向 waitingList 动态数组的指针 return 指向 Main。我怎样才能做到这一点？我到处找过。帮助

Answer 1

你应该尝试做一个包含指针和传递的更高结构，return你的函数之间的结构，因为函数可以return只有一个object/structure，但是你的structure/object 可以包含更多 objects/structures

Answer 2

好的，这里有两种方法。

首先是，根据您的评论，您认为您的讲师会想要什么：

void
xregister(structure1 **registerArray, int *arrayCount,
    structure1 **waitingList, int *waitCount)
{

    // Bunch of code in here

    *arrayCount += 1;
    *registerArray = realloc(inspecao, *arrayCount * sizeof(structure1));

    // Doesn't matter what it does really
    eliminate(waitingList, 5, waitCount)
}

void
eliminate(structure1 **arrayToEliminateFrom, int positionToEliminate,
int *count)
{

    // The code for this doesn't matter

    *count -= 1;

    // All I do is eliminate an ellement and reallocate it
    *arrayToEliminateFrom = realloc(*arrayToEliminateFrom,
        *count * sizeof(structure1))
}

这是我和罗伯托的建议。实际上，我的是一种通用的可变长度数组方法，可以通过一些细微的字段更改来完全推广。在某种程度上，由于您已经在使用结构，所以我不明白为什么您的讲师会反对，因为这是一种标准的方法。更简洁更干净。

struct vector {
    int vec_count;
    structure1 *vec_base;
};

void
xregister(vector *registerArray,vector *waitingList)
{

    // Bunch of code in here

    registerArray->vec_count += 1;
    registerArray->vec_base = realloc(registerArray->vec_base,
        registerArray->vec_count * sizeof(structure1));

    // Doesn't matter what it does really
    eliminate(waitingList, 5)
}

void
eliminate(vector *arrayToEliminateFrom, int positionToEliminate)
{

    // The code for this doesn't matter

    arrayToEliminateFrom->vec_count -= 1;

    // All I do is eliminate an ellement and reallocate it
    arrayToEliminateFrom->vec_base = realloc(arrayToEliminateFrom->vec_base,
        arrayToEliminateFrom->vec_count * sizeof(structure1))
}

这里有一个更简洁的方法：

struct vector {
    int vec_count;
    structure1 *vec_base;
};

void
vecgrow(vector *vec,int inc)
{

    vec->vec_count += inc;
    vec->vec_base = realloc(vec->vec_base,vec->vec_count * sizeof(structure1));
}

void
xregister(vector *registerArray,vector *waitingList)
{

    // Bunch of code in here

    vecgrow(registerArray,1);

    // Doesn't matter what it does really
    eliminate(waitingList, 5)
}

void
eliminate(vector *arrayToEliminateFrom, int positionToEliminate)
{

    // The code for this doesn't matter

    vecgrow(arrayToEliminateFrom,-1);
}

返回两个指向动态数组的指针

Returning Two Pointers to Dynamic Arrays

c

arrays

pointers

dynamic-arrays