有关交换的问题 [英] A question about swap
问题描述
我希望这个问题不会出现两次。我尝试发布一次，
然而，我在谷歌上得到了一个愚蠢的505内部错误。当这个
发生时，帖子会在30分钟后发布，或者不会发布在
全部。
鉴于
void swap（int * x，int * y）
{
int temp;
temp = * x;
* x = * y;
* y = temp;
}
如果让一个临时变量允许任何东西与
本身安全交换？假设x = 10且y = 10.在没有
temp的情况下会发生什么？
Chad
I hope this question doesn''t appear twice. I tried posting it once,
however, I got a stupid 505 internal error on google. When this
happens, the post will either post 30 minutes later or won''t post at
all.
Given
void swap(int *x, int *y)
{
int temp;
temp = *x;
*x = *y;
*y = temp;
}
How does having a temp variable allow for anything to safely swap with
itself? Say x = 10 and y = 10. What would happen in the absence of
temp?
Chad
推荐答案
Chad写道：
Chad wrote:
我希望这个问题不会出现两次。我尝试发布一次，
然而，我在谷歌上得到了一个愚蠢的505内部错误。当这个
发生时，帖子会在30分钟后发布，或者不会发布在
全部。
鉴于
void swap（int * x，int * y）
{
int temp;
temp = * x;
* x = * y;
* y = temp;
}
如果让一个临时变量允许任何东西与
本身安全交换？假设x = 10且y = 10.在没有
temp的情况下会发生什么？
I hope this question doesn''t appear twice. I tried posting it once,
however, I got a stupid 505 internal error on google. When this
happens, the post will either post 30 minutes later or won''t post at
all.
Given
void swap(int *x, int *y)
{
int temp;
temp = *x;
*x = *y;
*y = temp;
}
How does having a temp variable allow for anything to safely swap with
itself? Say x = 10 and y = 10. What would happen in the absence of
temp?
尝试编写没有它的函数并查看你得到了什么。
-
Ian Collins。
Try writing the function without it and see what you get.
--
Ian Collins.
Chad< cd ** ***@gmail.com写：
Chad <cd*****@gmail.comwrites:
我希望这个问题不会出现两次。
I hope this question doesn''t appear twice.
[...]
确实如此。看看我对另一个的回复。
-
Keith Thompson（The_Other_Keith） ks *** @ mib.org < http://www.ghoti.net/~kst>
诺基亚
"我们必须做一点事。这是事情。因此，我们必须这样做。
- Antony Jay和Jonathan Lynn，是部长
[...]
It did. See my response to the other one.
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
Chad写道：
Chad wrote:
我希望这个问题不会出现两次。我尝试发布一次，
然而，我在谷歌上得到了一个愚蠢的505内部错误。当这个
发生时，帖子会在30分钟后发布，或者不会发布在
全部。
鉴于
void swap（int * x，int * y）
{
int temp;
temp = * x;
* x = * y;
* y = temp;
}
如果让一个临时变量允许任何东西与
本身安全交换？假设x = 10且y = 10.在没有
temp的情况下会发生什么？
I hope this question doesn''t appear twice. I tried posting it once,
however, I got a stupid 505 internal error on google. When this
happens, the post will either post 30 minutes later or won''t post at
all.
Given
void swap(int *x, int *y)
{
int temp;
temp = *x;
*x = *y;
*y = temp;
}
How does having a temp variable allow for anything to safely swap with
itself? Say x = 10 and y = 10. What would happen in the absence of
temp?
好吧，x'的价值将被无可挽回地覆盖，不是吗？如果你确实不喜欢临时变量，那么查找所谓的XOR
swap。
< http://en.wikipedia.org/wiki/XOR_swap_algorithm>
Well, x''s value will get irretrievably overwritten won''t it? If you
really dislike the temporary variable, then look-up the so-called "XOR
swap".
<http://en.wikipedia.org/wiki/XOR_swap_algorithm>
这篇关于有关交换的问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
