/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

0 vote220 views1 answer
Libc++abi.dylib: terminating with uncaught exception of type std::invalid_argument: stoi: no conversion
C++
21 votes203 views6 answers
Convert char to string c++
C++
0 vote182 views0 answer
C++
1 vote208 views1 answer
C++ split long code
C++
4 votes204 views2 answers
Max value of double c++
C++
0 vote196 views1 answer
C++ while true
C++
10 votes215 views2 answers
2d vector c++ declaration
C++
14 votes196 views3 answers
Initialising 2d vector
C++
0 vote197 views1 answer
C++ read entire file into a variable
C++
0 vote200 views1 answer
C++ rename function
C++