Mixed Chinese postman problem

The Mixed Chinese Postman Problem (MCPP) is a variation of the Chinese Postman Problem (CPP), a classical problem in graph theory. The problem involves finding a shortest closed tour (a circuit) that traverses every edge of a graph at least once. The mixed version of this problem includes both directed and undirected edges in the graph. ### Definitions: 1. **Graph Types**: - **Undirected Edges**: Edges where the order of traversal does not matter.