如何建立一个std :: vector< std :: string>然后排序？ [英] How can I build a std::vector<std::string> and then sort them?

问题描述

我有一堆字符串，我需要排序。我认为std :: vector将是最简单的方法来做到这一点。但是，我从来没有使用过向量，所以需要一些帮助。

I have a bunch of strings that I need to sort. I think a std::vector would be the easiest way to do this. However, I've never used vectors before and so would like some help.

我只需要对它们进行字母数字排序，没有什么特别的。事实上，string :: compare函数会工作。

I just need to sort them alphanumerically, nothing special. Indeed, the string::compare function would work.

之后，我如何迭代它们来验证它们是否排序？

After that, how can I iterate through them to verify that they're sorted?

这里是我到目前为止：

std::sort(data.begin(), data.end(), std::string::compare);

for(std::vector<std::string>::iterator i = data.begin(); i != data.end(); ++i)
{
    printf("%s\n", i.c_str);
}

推荐答案

p>

You can just do

std::sort(data.begin(), data.end());

它会排序你的字符串。然后通过它们检查它们是否有序

And it will sort your strings. Then go through them checking whether they are in order

if(names.empty())
    return true; // empty vector sorted correctly
for(std::vector<std::string>::iterator i=names.begin(), j=i+1; 
        j != names.end(); 
        ++i, ++j)
    if(*i > *j)
        return false;
return true; // sort verified

特别的， std :: string :: compare 不能用作比较器，因为它不会做 sort 要它做的事情：如果第一个参数小于第二个，否则返回false。如果你使用上面的 sort ，它只会使用 operator $ c> std :: string 使其返回 first.compare（second）< 0 ）。

In particular, std::string::compare couldn't be used as a comparator, because it doesn't do what sort wants it to do: Return true if the first argument is less than the second, and return false otherwise. If you use sort like above, it will just use operator<, which will do exactly that (i.e std::string makes it return first.compare(second) < 0).

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