Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
import sys

N = int(input())
As = [list(map(int,input().split())) for i in range(N)]
As = np.array(As)-1
current_waitings = As[:,0]
game_counter = np.zeros(N).astype('int')

day = 0
completed_players = []
res = N*(N-1)//2
while res:
    day_player = []
    no_game = True
    for i,e1 in enumerate(current_waitings):
        if i in completed_players or e1 in day_player or i in day_player:
            continue
        if current_waitings[e1] == i:
            no_game = False
            res -= 1
            day_player.append(i)
            day_player.append(e1)
            if game_counter[i] == N-2:
                completed_players.append(i)
            if game_counter[i] <= N-3:
                game_counter[i] += 1
            if game_counter[e1] == N-2:
                completed_players.append(e1)
            if game_counter[e1] <= N-3:
                game_counter[e1] += 1
            current_waitings[i] = As[i][game_counter[i]]
            current_waitings[e1] = As[e1][game_counter[e1]]
    if no_game:
        print(-1)
        sys.exit()
    day += 1
print(day)


Fixed submission:
from collections import deque
def solve():
    n = int(input())
    a = []
    for i in range(n):
        ai = [int(j)-1 for j in input().split()]
        a.append(deque(ai))
    d = set()
    q = deque()
    for i in range(n):
        ai = a[i].popleft()
        if i < ai:
            q.append((i, ai))
        else:
            q.append((ai, i))
    ans = 0
    while q:
        ans += 1
        nxt_q = deque()
        while q:
            i, ai = q.pop()
            if (i, ai) in d:
                if a[i]:
                    ni = a[i].popleft()
                    if i < ni:
                        nxt_q.append((i, ni))
                    else:
                        nxt_q.append((ni, i))
                if a[ai]:
                    ni = a[ai].popleft()
                    if ai < ni:
                        nxt_q.append((ai, ni))
                    else:
                        nxt_q.append((ni, ai))
            else:
                d.add((i, ai))
        q = nxt_q
    if any(i for i in a):
        ans = -1
    print(ans)

solve()

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
import sys

N = int(input())
As = [list(map(int,input().split())) for i in range(N)]

As = np.array(As)-1


current_waitings = As[:,0]

game_counter = np.zeros(N).astype('int')

day = 0
completed_players = []
res = N*(N-1)//2
while res:
    day_player = []
    no_game = True
    for i,e1 in enumerate(current_waitings):
        if i in completed_players:
            continue
        if current_waitings[e1] == i and e1 not in day_player and i not in day_player:
            no_game = False
            res -= 1
            day_player.append(i)
            day_player.append(e1)
            if game_counter[i] == N-2:
                completed_players.append(i)
            if game_counter[i] <= N-3:
                game_counter[i] += 1
            if game_counter[e1] == N-2:
                completed_players.append(e1)
            if game_counter[e1] <= N-3:
                game_counter[e1] += 1
            current_waitings[i] = As[i][game_counter[i]]
            current_waitings[e1] = As[e1][game_counter[e1]]
    if no_game:
        print(-1)
        sys.exit()
    day += 1
print(day)


Fixed submission:
from collections import deque
def solve():
    n = int(input())
    a = []
    for i in range(n):
        ai = [int(j)-1 for j in input().split()]
        a.append(deque(ai))
    d = set()
    q = deque()
    for i in range(n):
        ai = a[i].popleft()
        if i < ai:
            q.append((i, ai))
        else:
            q.append((ai, i))
    ans = 0
    while q:
        ans += 1
        nxt_q = deque()
        while q:
            i, ai = q.pop()
            if (i, ai) in d:
                if a[i]:
                    ni = a[i].popleft()
                    if i < ni:
                        nxt_q.append((i, ni))
                    else:
                        nxt_q.append((ni, i))
                if a[ai]:
                    ni = a[ai].popleft()
                    if ai < ni:
                        nxt_q.append((ai, ni))
                    else:
                        nxt_q.append((ni, ai))
            else:
                d.add((i, ai))
        q = nxt_q
    if any(i for i in a):
        ans = -1
    print(ans)

solve()

Buggy python submission (verdict: Runtime Error):
import numpy as np
import sys

N = int(input())
As = [list(map(int,input().split())) for i in range(N)]
As = np.array(As)-1


current_waitings = As[:,0]
game_counter = np.zeros(N).astype('int')

day = 0
completed_players = []
day_player = []
for x in range(N*(N+1)//2):
    day_player = []
    for i,e1 in enumerate(current_waitings):
        if i in completed_players:
            continue
        if current_waitings[e1] == i and e1 not in day_player and i not in day_player:
            day_player.append(i)
            day_player.append(e1)
            if game_counter[i] == N-2:
                completed_players.append(i)
            if game_counter[i] <= N-3:
                game_counter[i] += 1
            if game_counter[e1] == N-2:
                completed_players.append(e1)
            if game_counter[e1] <= N-3:
                game_counter[e1] += 1
            current_waitings[i] = As[i][game_counter[i]]
            current_waitings[e1] = As[e1][game_counter[e1]]
        if len(completed_players) == N:
            print(day+1)
            sys.exit()
    day += 1
print(-1)



Fixed submission:
from collections import deque
def solve():
    n = int(input())
    a = []
    for i in range(n):
        ai = [int(j)-1 for j in input().split()]
        a.append(deque(ai))
    d = set()
    q = deque()
    for i in range(n):
        ai = a[i].popleft()
        if i < ai:
            q.append((i, ai))
        else:
            q.append((ai, i))
    ans = 0
    while q:
        ans += 1
        nxt_q = deque()
        while q:
            i, ai = q.pop()
            if (i, ai) in d:
                if a[i]:
                    ni = a[i].popleft()
                    if i < ni:
                        nxt_q.append((i, ni))
                    else:
                        nxt_q.append((ni, i))
                if a[ai]:
                    ni = a[ai].popleft()
                    if ai < ni:
                        nxt_q.append((ai, ni))
                    else:
                        nxt_q.append((ni, ai))
            else:
                d.add((i, ai))
        q = nxt_q
    if any(i for i in a):
        ans = -1
    print(ans)

solve()

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
import sys

N = int(input())
As = [list(map(int,input().split())) for i in range(N)]
As = np.array(As)-1


current_waitings = As[:,0]
game_counter = np.zeros(N).astype('int')

day = 0
completed_players = []
day_player = []
for x in range(N*(N-1)//2):
    day_player = []
    for i,e1 in enumerate(current_waitings):
        if i in completed_players:
            continue
        if current_waitings[e1] == i and e1 not in day_player and i not in day_player:
            day_player.append(i)
            day_player.append(e1)
            if game_counter[i] == N-2:
                completed_players.append(i)
            if game_counter[i] <= N-3:
                game_counter[i] += 1
            if game_counter[e1] == N-2:
                completed_players.append(e1)
            if game_counter[e1] <= N-3:
                game_counter[e1] += 1
            current_waitings[i] = As[i][game_counter[i]]
            current_waitings[e1] = As[e1][game_counter[e1]]
        if len(completed_players) == N:
            print(day+1)
            sys.exit()
    day += 1
print(-1)



Fixed submission:
from collections import deque
def solve():
    n = int(input())
    a = []
    for i in range(n):
        ai = [int(j)-1 for j in input().split()]
        a.append(deque(ai))
    d = set()
    q = deque()
    for i in range(n):
        ai = a[i].popleft()
        if i < ai:
            q.append((i, ai))
        else:
            q.append((ai, i))
    ans = 0
    while q:
        ans += 1
        nxt_q = deque()
        while q:
            i, ai = q.pop()
            if (i, ai) in d:
                if a[i]:
                    ni = a[i].popleft()
                    if i < ni:
                        nxt_q.append((i, ni))
                    else:
                        nxt_q.append((ni, i))
                if a[ai]:
                    ni = a[ai].popleft()
                    if ai < ni:
                        nxt_q.append((ai, ni))
                    else:
                        nxt_q.append((ni, ai))
            else:
                d.add((i, ai))
        q = nxt_q
    if any(i for i in a):
        ans = -1
    print(ans)

solve()