Submission #147154

#	Time	Username	Problem	Language	Result	Execution time	Memory
147154		jh05013	Wand (COCI19_wand)	Pypy 2	70 / 70	300 ms	31252 KiB

wand

from __future__ import print_function
input = raw_input
range = xrange

n, m = map(int,input().split())
adj = [[] for i in range(n+1)]
for i in range(m):
    a, b = map(int,input().split())
    adj[b].append(a)

if not adj[1]:
    print('1' + '0'*(n-1))
    exit()

vis = [False]*(n+1); vis[1] = True
stack = [1]
while stack:
    p = stack.pop()
    for q in adj[p]:
        if vis[q]: continue
        vis[q] = True; stack.append(q)
vis[1] = any((vis[p] and (1 in adj[p])) for p in range(2, n+1))

for x in vis[1:]:
    print(int(x), end='')

• Subtask 1: 70 / 70