# edge.py

# From Classic Computer Science Problems in Python Chapter 4

# Copyright 2018 David Kopec

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

from __future__ import annotations

from dataclasses import dataclass

@dataclass

class Edge:

u: int # the "from" vertex

v: int # the "to" vertex

def reversed(self) -> Edge:

return Edge(self.v, self.u)

def __str__(self) -> str:

return f"{self.u} -> {self.v}"