feat: a different implementation of checking bipartite-ness of a graph

[tushar2407]

Description of Change

I have implemented a recursive solution to check whether the given graph is bipartite or not.

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Added documentation so that the program is self-explanatory and educational - Doxygen guidelines
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes:

[Panquesito7]

Great work! 😄👍

[Panquesito7]

LGTM 🚀 Thank you for your contribution! 😄👍

[ayaankhan98]

test.cpp: In function ‘bool graph::checkBipartite(std::vector<std::vector<long int> >, int64_t, std::vector<long int>)’:
test.cpp:42:22: error: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<long int>::size_type’ {aka ‘long unsigned int’} [-Werror=sign-compare]
   42 |         for(int i=0;i<graph[u].size();i++)
      |                     ~^~~~~~~~~~~~~~~~
test.cpp: In function ‘bool graph::isBipartite(std::vector<std::vector<long int> >)’:
test.cpp:67:18: error: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<std::vector<long int> >::size_type’ {aka ‘long unsigned int’} [-Werror=sign-compare]
   67 |     for(int i=0;i<graph.size();i++)
      |                 ~^~~~~~~~~~~~~
cc1plus: all warnings being treated as errors

shell returned 1

[Panquesito7]

LGTM 🚀 Please review again, @ayaankhan98.