Update app.py

app.py

@@ -25,6 +25,8 @@ def draw_graph(G, pos=None, title="Graph Visualization"):
     nx.draw(G, pos=pos, with_labels=True, node_color='lightblue', node_size=500, font_size=10, font_weight='bold')
     st.pyplot(plt)
 
+from networkx.algorithms.approximation import christofides
+
 # Function to display Traveling Salesman Problem
 def display_tsp():
     st.title("Drawing: Traveling Salesman Problem")
@@ -48,7 +50,8 @@ def display_tsp():
                 dist = dist
                 G.add_edge(i, j, weight=dist)
 
-        cycle = nx.christofides(G, weight="weight")
+        # Find TSP cycle using Christofides' approximation
+        cycle = christofides(G, weight="weight")
         edge_list = list(nx.utils.pairwise(cycle))
 
         # Draw closest edges on each node only
@@ -90,7 +93,7 @@ def display_tsp():
                 G_custom.add_edge(i, j, weight=dist)
 
         # Find TSP cycle using Christofides' approximation
-        cycle = nx_app.christofides(G_custom, weight="weight")
+        cycle = christofides(G_custom, weight="weight")
         edge_list = list(nx.utils.pairwise(cycle))
 
         # Draw closest edges on each node only