In C$++,$ you will need to address three $($or four, but only if you feel like it$)$ of these classic algorithms, as follows:Comment to identify and very briefly explain the algorithmImplement the algorithm using the style described belowOutput the Big$-$O time complexity of the algorithmPlace each algorithm in its own function $($you may add helper function$/$s$,$ as needed$).$Use 'left' and 'right' as your counter variables in place of $\text{'}$i$\text{'}$ and $\text{'}$j$\text{'}$ as your outside counter and your inside counter, respectively. $($These colloquially refer to one's left index finger and right index finger keeping track of the problem and solution as the person progresses through it$.)$ Use $\text{'}$n$\text{'}$ as your size$-$of$-$the$-$problem variable in order to match up to the use of n in Chapter $3$ of our textbook.This is a demo program, so the main can announce the demonstration of the algorithms, then demonstrate and call each one to show that they work.Your Big$-$O report can be done as you wish, easy or hard, such ascout $<<$ "The time complexity of the XX algorithm is O$($n lg n$)."<<$ endl;cout $<<$ "Timing one hundred trials of XX algorithm, we find an average time complexity of O$("<<$ complexity $<<"),$ compared to the expected O$($n lg n$)."<<$ endl;