Optimize Median method from TC O(N log N) to Linear Time Complexity

[mohammedelgammal]

implementing IntroSelect algorithm which merges between quickSelect and medianOfMedians algorithms with utilities functions dt_min named after lib name to prevent conflict and swap.

[AlexandreHiroyuki]

The CI broke with the following error:

src/DataTomeAnalysis.h: In member function ‘TypeOfArray DataTomeAnalysis<TypeOfArray, TypeOfSum>::medianOfMedians(int, int, TypeOfArray*)’:
src/DataTomeAnalysis.h:287:31: error: there are no arguments to ‘min’ that depend on a template parameter, so a declaration of ‘min’ must be available [-fpermissive]
  287 |         int left = i, right = min(i + k, r + 1),
      |                               ^~~

You have to include some library to use the min function.
I suggest you include the C library because Cpp-exclusive libraries can break the compilation for some specific devices.

[AlexandreHiroyuki]

New error:

Processing test_DataTomeAnalysis in desktop environment
--------------------------------------------------------------------------------
Building...
In file included from test/test_DataTomeAnalysis/DataTomeAnalysis.test.cpp:1:
In file included from src/DataTomeAnalysis.h:11:
src/DataTomeUtils.h:25:1: warning: 'auto' type specifier is a C++11 extension [-Wc++11-extensions]
auto dt_min(const T1 &a, const T2 &b) -> decltype(a < b ? a : b) {
^
src/DataTomeUtils.h:25:1: error: 'auto' not allowed in function return type
auto dt_min(const T1 &a, const T2 &b) -> decltype(a < b ? a : b) {
^~~~
src/DataTomeUtils.h:25:38: error: expected ';' at end of declaration
auto dt_min(const T1 &a, const T2 &b) -> decltype(a < b ? a : b) {
                                     ^
                                     ;
src/DataTomeUtils.h:25:39: error: cannot use arrow operator on a type
auto dt_min(const T1 &a, const T2 &b) -> decltype(a < b ? a : b) {
                                      ^
In file included from test/test_DataTomeAnalysis/DataTomeAnalysis.test.cpp:1:
src/DataTomeAnalysis.h:287:31: error: no matching function for call to 'dt_min'
        int left = i, right = dt_min(i + k, r + 1),
                              ^~~~~~
1 warning and 4 errors generated.
*** [.pio/build/desktop/test/test_DataTomeAnalysis/DataTomeAnalysis.test.o] Error 1
Building stage has failed, see errors above. Use `pio test -vvv` option to enable verbose output.
---------- desktop:test_DataTomeAnalysis [ERRORED] Took 0.50 seconds ----------

It seems like the auto keyword is not supported on the version we need.

[mohammedelgammal]

Refactored dt_min and CI tests ran successfully

[AlexandreHiroyuki]

LGTM