作为函数参数传递的数组的大小 [英] sizeof an array passed as function argument

问题描述

可能的重复:
函数参数中数组的长度

我正在做作业，我完全被难住了.我们假设列表的每个顺序都是一个整数数组，所以我根据老师的伪代码编写了这段代码:

Hi am doing homework and I am completly stumped. We were suppose to get every order of a list an array of integers so I wrote this piece of code, based off of my teacher's pseudocode:

void permute(int v[], int curr,char letters[])
{
    if(curr >= sizeof(v)/sizeof(int))
    {
        checkit(v,letters);
    }
    for(int i = curr; i < sizeof(v)/sizeof(int); i++)
    {
        swap(i,curr,v);
        permute(v,curr + 1,letters);
        swap(v[curr],v[i]);
    }//for
}//permu

我唯一不确定的是 sizeof(v)/sizeof(int) 是否正确.

The only thing I am not sure of is if sizeof(v)/sizeof(int) is the right way to go.

推荐答案

sizeof(v)/sizeof(int) 不是要走的路.您的函数完全等同于:

sizeof(v)/sizeof(int) is not the way to go. Your function is exactly equivalent to:

void permute(int *v, int curr, char *letters)
{
    ...
}

即v 不是真正的数组，它是一个指针.你不能在 C 或 C++ 中传递数组.

i.e. v is not really an array, it's a pointer. You cannot pass arrays in C or C++.

解决方案是以下之一(并非详尽无遗):

The solution is one of the following (not exhaustive):

• 添加一个额外的参数来明确描述数组的长度
• 添加一个指向数组最后一个元素的额外参数
• 使用合适的容器(例如 std::vector)，您可以在其上调用 size()
• @sehe 建议的模板解决方案

• add an extra argument that explicitly describes the length of the array
• add an extra argument that points at the last element of the array
• use a proper container (e.g. std::vector), which you can call size() on
• the template solution that @sehe suggests

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