Cyclic Cities Exploration

You are given a directed graph representing a set of cities (nodes) and flights (edges). Your task is to determine whether there is a cycle in the graph. If there is a cycle, you should return 'Yes', otherwise return 'No'. Input Format: - The first line contains an integer n, the number of cities. - The next lines describe edges in the form of 'u -> v', where u and v are city indices starting from 0, representing a flight from city u to city v. The input ends when a line containing 'END' is encountered. Output Format: - Print 'Yes' if there is a cycle in the graph, otherwise print 'No'. Example Input: 4 0 1 1 2 2 0 3 1 END Example Output: Yes