[FEATURE] Negative weight cycle detection

[ayaankhan98]

Detailed Description

it looks like we don't have any algorithm to detect the negative weight cycle in graphs

Possible Implementation

we can implemnt this using Bellaman-Ford algorithm.
Bellaman-Ford Algorithm gives the shortest path from a given source node to all other nodes in |V|-1 iterations (where V is the number of vertex or nodes in graph), if we perform one more iteration of Bellaman-Ford algorithm that is the V-th iteration and if distance of any node gets improved in this V-th iteration then it seems like we have a negative cycle in the graph

[cclauss]

https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/dynamic_programming/Bellman-Ford.cpp