Add famous code in cpp

[brat-blip]

this issue is about to add famous codes of problem or techniques in cpp that are beneficial in programing

[brat-blip]

@benedictprajwal please add hacktoberfest accepted tag in this issue

[brat-blip]

@benedictprajwal please assign this issue to me

[imNilabja]

I would like to do this task,can you assign me.

[Jyotisaini-2001]

I am interested to add some famous code in Cpp. Can you please assign me this issue?

[Pushkariiit]

please assign this issue to me i will be uplaoding all the popular codes of dynamic programming in easy to understand way.

[Code-2k2]

I would like to add popular graph related algorithms. Please assign the issue to me.