C++ Taskbook Level 5.8

Given an array:

cpp{
  {2, 1, 4, 3, 5},
  {3, 5, 2, 4, 1},
  {4, 3, 1, 5, 2},
}

Sort the elements in each subarray.

Given some array of numbers, for example, like this:

cppint arr[] = [1, 2, 3, 4, 5, 6];

Merge pairs of elements together:

cppint[] [12, 34, 56]

Display the following pyramid on the screen: