Chain Reactions Solution

Author: deeptimi

chainreactions.py3

@@ -0,0 +1,20 @@
+def chain_reaction():
+    N = int(input())
+    F = [0]+list(map(int, input().split()))
+    P = list(map(int, input().split()))
+    adj = [[] for _ in range(N+1)]
+    for u, v in enumerate(P, 1):
+        adj[v].append(u)
+    result = 0
+    for v in reversed(range(N)):
+        if not adj[v]:
+            continue
+        u = min(adj[v], key=F.__getitem__)
+        F[v] = max(F[v], F[u])
+        result += sum(F[nu] for nu in adj[v] if nu != u)
+    result += F[0]
+    return result
+
+for case in range(int(input())):
+    print('Case #%d: %s' % (case+1, chain_reaction()))
+