相关疑难解决方法(0)

给定STL向量,仅按排序顺序输出重复项,例如,

INPUT : { 4, 4, 1, 2, 3, 2, 3 }
OUTPUT: { 2, 3, 4 }

该算法很简单,但目标是使其与std :: unique()一样高效.我天真的实现就地修改了容器:

我天真的实施:

void not_unique(vector<int>* pv)
{
    if (!pv)
        return;

 // Sort (in-place) so we can find duplicates in linear time
 sort(pv->begin(), pv->end());

 vector<int>::iterator it_start = pv->begin();
 while (it_start != pv->end())
 {
  size_t nKeep = 0;

  // Find the next different element
  vector<int>::iterator it_stop = it_start + 1;
  while (it_stop != pv->end() && *it_start == *it_stop)
  {
   nKeep = 1; // …