Fixed a bug in the stack where if we add to stack without setting them to visited, it could be counted more than once because some other vertex could add the same neighbour because its flag is not set to true
Fixed a bug in the stack where if we add to stack without setting them to visited, it could be counted more than once because some other vertex could add the same neighbour because its flag is not set to true

sunilgaikwad/coderunner,sunilgaikwad/coderunner