Counting cycles in an undirected graph using DFS-XOR algorithm

We present an algorithm for counting the number of cycles in an undirected graph. The given algorithm generates exact results but it is not guaranteed to run in a polynomial time. Afterwards, an approximated version from the algorithm guaranteed to run in a polynomial time was introduced. The obtained results was used to measure the entropy of graphs. Entropy represents robustness of the graph under analysis. An experiment is conducted to compare the results of our algorithm with the results of another algorithm based on the Donald Johnson backtracking algorithm.