我有一个带有单词列表的文本文件。
我使用ifstream
将这些单词读成vector
,现在我尝试按类似于以下的顺序对它们进行排序:
A a B b C c [...]
我尝试在气泡搜索算法内部使用第三个for循环来实现此功能,以查看每个单词的第一个字符(我知道这与最有效的方式相去甚远,尤其是在使用大型数据集的情况下)
然后检查字母和下一个字母是大写还是小写,并切换大写字母是否与当前字母相同,但这似乎不起作用。
void bubble_Sort (vector <string> & words)
{
for (unsigned i = words.size(); i >= 2; --i)
{
for (unsigned k = 0; k + 1 < i; k++)
{
int hi = k+1;
string temp1 = words[hi];
string temp2 = words[k];
int smallsize = words[hi].size();
int smallprecedence = 0;
if (words[k].size() < words[hi].size())
smallsize = words[k].size();
for (unsigned j = 0; j < smallsize; j++)
{
if (temp1[j] >= 'A' && temp1[j] <= 'Z')
{
if (temp2[j] >='a' && temp2[j] <= 'z')
{
char lowercase1 = temp1[j] + 32;
if (lowercase1 == temp2[j])
{
string temp = words[k];
words[k] = words[hi];
words[hi] = temp;
break;
}
}
else if (temp2[j] >= 'A' && temp2[j] <= 'Z')
{
if (temp1[j] < temp2[j])
{
string temp = words[k];
words[k] = words[hi];
words[hi] = temp;
break;
}
}
}
if (temp1[j] >= 'a' && temp1[j] <= 'z')
{
if (temp2[j] >= 'A' && temp2[j] <= 'Z')
{
char uppercase1 = temp1[j] - 32;
if (uppercase1 < temp2[j])
{
string temp = words[k];
words[k] = words[hi];
words[hi] = temp;
break;
}
}
else if (temp2[j] >= 'a' && temp2[j] <= 'z')
{
if (temp1[j] < temp2[j])
{
string temp = words[k];
words[k] = words[hi];
words[hi] = temp;
break;
}
}
}
else if (temp1[j] == temp2[j] && temp1.size() < temp2.size())
++smallprecedence;
}
if (smallprecedence == smallsize)
{
string temporary = words[k];
words[k] = words[hi];
words[hi] = temporary;
}
}
}
}
最佳答案
不要重新发明轮子。只需修改默认比较功能,以使aA
编辑我使用了错误的比较功能。对于true
,应返回<
;对于false
,应返回>=
。该问题已解决
std::vector<std::string> vec;
//
std::sort(vec.begin(), vec.end(), [](const std::string& lhs, const std::string& rhs)
{
const char* s1=lhs.c_str();
const char* s2=rhs.c_str();
while(true) {
// first ignore case
if ( std::toupper(*s1) < std::toupper(*s2) ) return true;
if ( std::toupper(*s1) > std::toupper(*s2) ) return false;
// end of both strings, exact match
if ( *s1 == 0 && *s2 == 0 ) return false;
// compare upper case vs lower case ('A' vs 'a')
if ( *s1 > *s2) return false;
if ( *s1 < *s2) return true;
++s1; ++s2;
}
});