c++ sort keeping track of indices
algorithm, c++, sorting, stl
Solution
Using C++11, the following should work just fine:
template <typename T>
std::vector<size_t> ordered(std::vector<T> const& values) {
std::vector<size_t> indices(values.size());
std::iota(begin(indices), end(indices), static_cast<size_t>(0));
std::sort(
begin(indices), end(indices),
[&](size_t a, size_t b) { return values[a] < values[b]; }
);
return indices;
}
Problem
Do you have some efficient routine for returning array with indices for sorted elements in a array? I think that some convenient way exists using stl `vector`. Do you have already implemented an efficient algo without stl, or do you have a reference to pseudo code or C++ code?