How to save position of min_element result?

Question

How can I save the value of min_element? It says it's a forward iterator but I can't seem to figure out how to save (assign to a variable to) it. I want to be able to access it by location in the vector. All I can find is examples of using the actual element (using *min_element() ). I tried

iterator< forward_iterator_tag, vector<string> > min_word_iterator = min_element(first_words_in_subvecs.begin(), first_words_in_subvecs.end());

but that didn't work. I'm going to replace the element at that index with a different element.

Answer 1

Use this:

std::vector<T>::iterator minIt = std::min_element(v.begin(),v.end());
//where T is the type of elements in vector v.

T minElement = *minIt; //or T & minElement = *minIt; to avoid copy!

And in C++11 (if your compiler supports auto keyword), then this:

auto minIt = std::min_element(v.begin(), v.end());
//type of minIt will be inferred by the compiler itself

T minElement = *minIt; //or auto minElement = *minIt;
                       //or auto & minElement = *minIt; to avoid copy

Answer 2

You can use the distance provided by stl to find the position. You need to pass the iterator returned by min_element to it to get the position

See this example code

#include <iostream>
#include <iterator>
#include <algorithm>
#include <vector>
using namespace std;

int main () {
  vector<int> myvec;
  int i = 0;
  for (i=8; i>0; i--)
  {
      myvec.push_back (i*10);
  }

  for (i=0; i<8; i++)
  {
      cout<<"At pos :"<<i<<"|val is:"<<myvec.at(i)<<endl;
  }

  int min_pos = distance(myvec.begin(),min_element(myvec.begin(),myvec.end()));
  cout << "The distance is: " << min_pos << "|value is "<<*min_element(myvec.begin(),myvec.end())<<endl;

  return 0;
}

Answer 3

When you have two random access iterators, you can generally subtract one from the other to find the distance between them. Thus, once you've got the iterator it , you can find the index of the element it refers to with it - my_vector.begin() .