upload exercise files

destroy_p3.py

@@ -0,0 +1,41 @@
+import numpy as np
+import networkx as nx
+import argparse
+
+parser=argparse.ArgumentParser(description='')
+parser.add_argument('-g', '--graph', dest='graph', action='store', default=None)
+args=parser.parse_args()
+
+if not args.graph:
+    print ("need a graph as input")
+    exit()
+
+def read_graph(graph_file):
+    with open(graph_file) as f:
+        n=int(f.readline())
+        m=int(f.readline())
+        A=[[0]*n for _ in range(n)]
+        for _ in range(m):
+            [u,v]=map(int, f.readline().split())
+            A[u][v]=1
+            A[v][u]=1
+    G=nx.Graph(np.array(A))
+    return G
+
+def max_comp_size(G):
+    return max([len(c) for c in nx.connected_components(G)])
+
+del_list=[]    
+G=read_graph(args.graph)
+n=len(G.nodes)
+while max_comp_size(G) > n/2:
+    u=np.random.choice(G.nodes)
+    if u not in del_list:
+        del_list.append(u)
+        G.remove_node(u)
+
+#print len(del_list), del_list
+
+
+for u in del_list:
+    print (u)