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

问题描述

可能重复：

函数参数中数组的长度

做家庭作业和我完全被困住。我们假设让列表的每个顺序都是一个整数数组，所以我根据我的老师的伪代码写了这段代码：

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

不确定是 sizeof（v）/ sizeof（int）是正确的方法。

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。您的函数完全等效于：

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

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

ie v 不是一个真正的数组，它是一个指针。您不能以C或C ++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（不完全）：

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

• 添加一个额外的参数，明确描述数组的长度


• 添加一个额外的参数指向数组的最后一个元素


• 使用合适的容器（例如 std :: vector ），您可以调用 size（）

• 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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