/C++/C++ sorting and keeping track of indexes

C++ sorting and keeping track of indexes

#include <iostream>
#include <vector>
#include <numeric>      // std::iota
#include <algorithm>    // std::sort, std::stable_sort

using namespace std;

template <typename T>
vector<size_t> sort_indexes(const vector<T> &v) {

  // initialize original index locations
  vector<size_t> idx(v.size());
  iota(idx.begin(), idx.end(), 0);

  // sort indexes based on comparing values in v
  // using std::stable_sort instead of std::sort
  // to avoid unnecessary index re-orderings
  // when v contains elements of equal values 
  stable_sort(idx.begin(), idx.end(),
       [&v](size_t i1, size_t i2) {return v[i1] < v[i2];});

  return idx;
}

Source: stackoverflow.com

Similar codes

2 votes163 views3 answers
Digit sum c++
C++
6 votes162 views1 answer
How to dynamically allocate an array c++
C++
1 vote164 views3 answers
Return use in c++
C++
2 votes178 views2 answers
Decltype in c++
C++
1 vote164 views1 answer
Chrono library c++
C++
-1 vote190 views1 answer
C++ set console title
C++
36 votes179 views2 answers
Remove at index vector c++
C++
1 vote154 views2 answers
C++ array sort method
C++
0 vote180 views1 answer
C++ simple projects
C++
1 vote144 views1 answer
Is C++ useful in 2021
C++