Problem p02684 (python)

Fixed submission:
N , K = map(int,input().split())
 
A = list(map(int,input().split()))
 
reach = [-1 for i in range(N)]
reach[0] = 0 #最初の町は0回でいく
now = 0
#loop = 1
dic ={}
dic[0] = 0
for i in range(N):
  to = A[now]-1
  if reach[to] != -1:
    ini = i+1
    #print(i,to,reach[to])
    loop = i+1 - reach[to]
    break
  if i+1 not in dic:
    dic[i+1] = to
  reach[to] = i+1
  #loop += 1
  now = to
 
 
#print(dic,reach,loop,ini)
if K < ini:
  print(dic[K]+1)
else:
  t = (ini-loop) + (K-ini)%loop
  print(dic[t]+1)

Buggy submission (verdict: Runtime Error):
N, K = map(int,input().split())
A = list(map(int,input().split()))
B = [0];BB=[0]
S = set([]);S.add(0)
now = 0
Flag = False
loop_start = -1
if K <= 2*pow(10,5)+10:
  for i in range(K):
    nxt = A[now]-1
    BB.append(nxt)
    now = nxt
  #print(BB)
  print(BB[K]+1)
  exit()
for i in range(N*2):
  nxt = A[now]-1
  #print(now,nxt)
  if nxt in S:
    if Flag:
      if nxt == loop_start:
        #print(nxt,i)
        loop_cycle = i-loop_num
        break
    else:
      loop_start = nxt
      loop_num = i
      Flag = True
  else:
    B.append(nxt);S.add(nxt)
  now = nxt
#print(B,loop_start,loop_cycle,loop_num)
loc = (K-loop_start)%loop_cycle+loop_num
#print(loc)
#print(len(B))
print(B[loc]+1)

Buggy submission (verdict: Runtime Error):
N, K = map(int,input().split())
A = list(map(int,input().split()))
B = [0]
S = set([]);S.add(0)
now = 0
Flag = False
loop_start = -1
if K <= 2*pow(10,5)+10:
  for i in range(K):
    nxt = A[now]-1
    B.append(nxt)
    now = nxt
  #print(B)
  print(B[K]+1)
  exit()
for i in range(N*2):
  nxt = A[now]-1
  #print(now,nxt)
  if nxt in S:
    if Flag:
      if nxt == loop_start:
        #print(nxt,i)
        loop_cycle = i-loop_num
        break
    else:
      loop_start = nxt
      loop_num = i
      Flag = True
  else:
    B.append(nxt);S.add(nxt)
  now = nxt
#print(B,loop_start,loop_cycle,loop_num)
loc = (K-loop_start)%loop_cycle+loop_start
#print(loc)
print(B[loc]+1)

Buggy submission (verdict: Runtime Error):
N, K = map(int,input().split())
A = list(map(int,input().split()))
B = [0]
S = set([]);S.add(0)
now = 0
Flag = False
loop_start = -1
if K <= 2*pow(10,5)+10:
  for i in range(K):
    nxt = A[now]-1
    B.append(nxt)
    now = nxt
  #print(B)
  print(B[K]+1)
  exit()
for i in range(K*2):
  nxt = A[now]-1
  #print(now,nxt)
  if nxt in S:
    if Flag:
      if nxt == loop_start:
        #print(nxt,i)
        loop_cycle = i-loop_num
        break
    else:
      loop_start = nxt
      loop_num = i
      Flag = True
  else:
    B.append(nxt);S.add(nxt)
  now = nxt
#print(B,loop_start,loop_cycle,loop_num)
loc = (K-loop_start)%loop_cycle+loop_start
#print(loc)
print(B[loc]+1)

Buggy submission (verdict: Runtime Error):
N, K = map(int,input().split())
A = list(map(int,input().split()))
B = [0]
S = set([]);S.add(0)
now = 0
Flag = False
loop_start = -1
if K <= 2*pow(10,5)+10:
  for i in range(K):
    nxt = A[now]-1
    B.append(nxt)
    now = nxt
  print(B)
  print(B[K]+1)
  exit()
for i in range(K):
  nxt = A[now]-1
  #print(now,nxt)
  if nxt in S:
    if Flag:
      if nxt == loop_start:
        #print(nxt,i)
        loop_cycle = i-loop_num
        break
    else:
      loop_start = nxt
      loop_num = i
      Flag = True
  else:
    B.append(nxt);S.add(nxt)
  now = nxt
#print(B,loop_start,loop_cycle,loop_num)
loc = (K-loop_start)%loop_cycle+loop_start
#print(loc)
print(B[loc]+1)

Buggy submission (verdict: Runtime Error):
N , K = map(int,input().split())

A = list(map(int,input().split()))

reach = [-1 for i in range(N)]
reach[0] = 0 #最初の町は0回でいく
now = 0
#loop = 1
dic ={}
dic[0] = 0
for i in range(N+1):
  to = A[now]-1
  if reach[to] != -1:
    ini = i+1
    #print(i,to,reach[to])
    loop = i+1 - reach[to]
    break
  if i+1 not in dic:
    dic[i+1] = to
  reach[to] = i+1
  #loop += 1
  now = to


#print(dic,reach,loop,ini)
if K <= ini:
  print(dic[K]+1)
else:
  t = (ini-loop) + (K-ini)%loop
  print(dic[t]+1)

Buggy submission (verdict: Runtime Error):
N , K = map(int,input().split())

A = list(map(int,input().split()))

reach = [-1 for i in range(N)]
reach[0] = 0 #最初の町は0回でいく
now = 0
#loop = 1
dic ={}
dic[0] = 0
for i in range(N+1):
  to = A[now]-1
  if reach[to] != -1:
    ini = i+1
    #print(i,to,reach[to])
    loop = i+1 - reach[to]
    break
  if i+1 not in dic:
    dic[i+1] = to
  reach[to] = i+1
  #loop += 1
  now = to


print(dic,reach,loop,ini)
if K <= ini:
  print(dic[K]+1)
else:
  t = (ini-loop) + (K-ini)%loop
  print(dic[t]+1)

Buggy submission (verdict: Runtime Error):
N , K = map(int,input().split())

A = list(map(int,input().split()))

reach = [-1 for i in range(N)]
reach[0] = 0 #最初の町は0回でいく
now = 0
#loop = 1
dic ={}
dic[0] = 0
for i in range(N):
  to = A[now]-1
  if reach[to] != -1:
    ini = i+1
    #print(i,to,reach[to])
    loop = i+1 - reach[to]
    break
  if i+1 not in dic:
    dic[i+1] = to
  reach[to] = i+1
  #loop += 1
  now = to


#print(dic,reach,loop,ini)
if K <= ini:
  print(dic[K]+1)
else:
  t = (ini-loop) + (K-ini)%loop
  print(dic[t]+1)