Graph

src/Graph/graph.py

@@ -0,0 +1,69 @@
+class Graph:
+    def __init__(self, directed: bool = False) -> None:
+        self.adjacency_list: dict[str, list[str]] = {}
+        self.directed: bool = directed
+        self.vertices: set[str] = set()
+
+    def add_edge(self, vertex_1: str, vertex_2: str):
+        if vertex_1 not in self.adjacency_list:
+            self.adjacency_list[vertex_1] = []
+        self.adjacency_list[vertex_1].append(vertex_2)
+        self.vertices.add(vertex_1)
+        self.vertices.add(vertex_2)
+
+        if vertex_2 not in self.adjacency_list:
+            self.adjacency_list[vertex_2] = []
+
+        if not self.directed:
+            self.adjacency_list[vertex_2].append(vertex_1)
+
+    def add_vertex(self, vertex: str):
+        if vertex not in self.adjacency_list:
+            self.adjacency_list[vertex] = []
+        self.vertices.add(vertex)
+
+    def dfs(self, start_vertex) -> list[str]:
+        if start_vertex not in self.vertices:
+            return []
+
+        visited = []
+        stack = [start_vertex]
+        seen = set()
+
+        while stack:
+            vertex = stack.pop()
+
+            if vertex not in seen:
+                visited.append(vertex)
+                seen.add(vertex)
+
+                neighbors = self.adjacency_list.get(vertex, [])
+
+                for index in range(len(neighbors) - 1, -1, -1):
+                    neighbor = neighbors[index]
+                    if neighbor not in seen:
+                        stack.append(neighbor)
+
+        return visited
+
+    def __iter__(self):
+        all_vertices = list(self.vertices)
+
+        if not all_vertices:
+            return iter([])
+
+        dfs_order = self.dfs(all_vertices[0])
+
+        return iter(dfs_order)
+
+    def __str__(self) -> str:
+        result = []
+        result.append(f"Graph (oriented: {self.directed})")
+        result.append("Adjacency list:")
+
+        vertices = sorted(self.adjacency_list.keys())
+        for vertex in vertices:
+            neighbors = self.adjacency_list[vertex]
+            result.append(f"  {vertex}: {neighbors}")
+
+        return "\n".join(result)