Submission #66767661

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from collections import deque
import sys
sys.setrecursionlimit(10**7)
N, M = map(int, input().split())
graph = [[] for _ in range(N)]
edges = []
for _ in range(M):
    u, v, w = map(int, input().split())
    u -= 1; v -= 1
    graph[u].append((v, w))
    edges.append((u, v, w))
INF = -1
d = [INF] * N
dq = deque([0])
d[0] = 0
while dq:
    u = dq.popleft()
    for v, w in graph[u]:
        if d[v] == INF:
 
 
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from collections import deque
import sys
sys.setrecursionlimit(10**7)

N, M = map(int, input().split())
graph = [[] for _ in range(N)]
edges = []
for _ in range(M):
    u, v, w = map(int, input().split())
    u -= 1; v -= 1
    graph[u].append((v, w))
    edges.append((u, v, w))

INF = -1
d = [INF] * N
dq = deque([0])
d[0] = 0
while dq:
    u = dq.popleft()
    for v, w in graph[u]:
        if d[v] == INF:
            d[v] = d[u] ^ w
            dq.append(v)

if d[N-1] == INF:
    print(-1)
    exit()

cycles = []
for u, v, w in edges:
    if d[u] != INF and d[v] != INF:
        x = d[u] ^ w ^ d[v]
        if x:
            cycles.append(x)

def build_basis(xs):
    B = []
    for x in sorted(xs, reverse=True):
        for b in B:
            x = min(x, x ^ b)
        if x:
            B.append(x)
    return B

basis = build_basis(cycles)

res = d[N-1]
for b in basis:
    res = min(res, res ^ b)

print(res)

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