added articulationPoint.cpp
added articulationPoint.cpp

Program to find articulation points/cut vertices in a graph
jorik041/algorepo,M4573R/algorepo,shubham7saxena/algorepo,calmhandtitan/algorepo,jorik041/algorepo,calmhandtitan/algorepo,M4573R/algorepo,shubham7saxena/algorepo