Submission #651712

#	Time	Username	Problem	Language	Result	Execution time	Memory
651712		beaconmc	Power Plant (JOI20_power)	Pypy 3	0 / 100	37 ms	18176 KiB

power

import sys

input = lambda: sys.stdin.readline().strip()
sys.setrecursionlimit(1000000000)


n = int(input())
if n==1:
    print(1)
    quit()
edges = [[] for i in range(n+1)]
par = [-1 for i in range(n+1)]
visited = [False for i in range(n+1)]
for i in range(n-1):
    a,b = map(int, input().split())
    edges[a].append(b)
    edges[b].append(a)
sus = input()

root = 1
flag = False

def dfs(a):
    for i in edges[a]:
        if not visited[i]:
            par[i] = a
            visited[i] = True
            dfs(i)
visited[root] = True
dfs(root)
dps = [-1 for i in range(n+1)]
used = [0 for i in range(n+1)]

ans = -1
def dp(a):
    global ans

    if dps[a] != -1:
        return dps[a]
    
    sum = 0
    maxi = 0
    for i in edges[a]:
        if i == par[a]: continue
        sum += dps[i]
        maxi = max(maxi, dps[i])
    
    if sus[a-1]=="1":
        ans = max(ans, maxi+1, sum-1)
    else:
        ans = max(ans,sum)
        
    dps[a] = max(sum-int(sus[a-1]), int(sus[a-1]))
    return dps[a]
        

dp(root)
print(ans)

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53