[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

graphs/dijkstra_2.py

@@ -1,21 +1,24 @@
 from typing import List
 
+
 def print_distances(distances: List[float]) -> None:
     print("\nVertex Distance")
     for vertex, distance in enumerate(distances):
         print(f"{vertex}\t{int(distance) if distance != float('inf') else 'INF'}")
 
+
 def find_min_distance(distances: List[float], visited: List[bool]) -> int:
     min_distance = float("inf")
     min_index = -1
-    
+
     for i in range(len(distances)):
         if not visited[i] and distances[i] < min_distance:
             min_distance = distances[i]
             min_index = i
-            
+
     return min_index
 
+
 def dijkstra(graph: List[List[float]], num_vertices: int, source: int) -> List[float]:
     distances = [float("inf")] * num_vertices
     visited = [False] * num_vertices
@@ -26,17 +29,21 @@ def dijkstra(graph: List[List[float]], num_vertices: int, source: int) -> List[f
         visited[u] = True
 
         for v in range(num_vertices):
-            if (not visited[v] and graph[u][v] != float("inf")
-                and distances[u] + graph[u][v] < distances[v]):
+            if (
+                not visited[v]
+                and graph[u][v] != float("inf")
+                and distances[u] + graph[u][v] < distances[v]
+            ):
                 distances[v] = distances[u] + graph[u][v]
 
     return distances
 
+
 def is_connected(graph: List[List[float]], num_vertices: int) -> bool:
     visited = [False] * num_vertices
     stack = [0]  # Start DFS from the first vertex
     visited[0] = True
-    
+
     while stack:
         node = stack.pop()
         for neighbor in range(num_vertices):
@@ -46,38 +53,43 @@ def is_connected(graph: List[List[float]], num_vertices: int) -> bool:
 
     return all(visited)
 
+
 def main() -> None:
     V = int(input("Enter number of vertices: ").strip())
     if V <= 0:
         print("Error: The number of vertices must be greater than 0.")
         return
-    
+
     E = int(input("Enter number of edges (must be >= V-1): ").strip())
     if E < V - 1:
-        print(f"Error: The number of edges must be at least {V - 1} for a connected graph.")
+        print(
+            f"Error: The number of edges must be at least {V - 1} for a connected graph."
+        )
         return
-    
+
     graph = [[float("inf")] * V for _ in range(V)]
-    
+
     for i in range(V):
         graph[i][i] = 0.0
 
     for i in range(E):
         print(f"\nEdge {i + 1}")
         src = int(input(f"Enter source (0 to {V - 1}): ").strip())
         dst = int(input(f"Enter destination (0 to {V - 1}): ").strip())
-        
+
         if src < 0 or src >= V or dst < 0 or dst >= V:
             print("Error: Source and destination must be valid vertex indices.")
             return
-        
+
         weight = float(input("Enter weight (non-negative): ").strip())
         if weight < 0:
             print("Error: Weight must be non-negative.")
             return
-        
+
         if src == dst:
-            print("Warning: Self-loop detected; it will be allowed but consider its implications.")
+            print(
+                "Warning: Self-loop detected; it will be allowed but consider its implications."
+            )
 
         # Handle duplicate edges: (optionally overwrite or warn)
         if graph[src][dst] != float("inf"):
@@ -86,7 +98,9 @@ def main() -> None:
         graph[src][dst] = weight
 
     if not is_connected(graph, V):
-        print("Warning: The graph is not connected. Dijkstra's algorithm may not yield valid results for all vertices.")
+        print(
+            "Warning: The graph is not connected. Dijkstra's algorithm may not yield valid results for all vertices."
+        )
 
     gsrc = int(input(f"\nEnter shortest path source (0 to {V - 1}): ").strip())
     if gsrc < 0 or gsrc >= V:
@@ -96,5 +110,6 @@ def main() -> None:
     distances = dijkstra(graph, V, gsrc)
     print_distances(distances)
 
+
 if __name__ == "__main__":
     main()