qyliang/CodeNanoFix huggingface dataset:
Buggy code:
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools
from collections import deque

sys.setrecursionlimit(10**7)
inf = 10**20
mod = 10**9 + 7

DR = [1, -1, 0, 0]
DC = [0, 0, 1, -1]

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()

G = []

def dfs(n, string, next_usable):
    if n == 0:
        G.append(string)
        return
    for char in next_usable:
        new_string = string + char
        if char == next_usable[-1]:
            added_char = chr(ord(char) + 1)
            next_usable += added_char
        dfs(n-1, new_string, next_usable)

def main():
    N = I()
    string = 'a'
    dfs(N, '', 'a')
    print(len(G))
    for string in G:
        print(string)


main()



Fixed code:
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools
from collections import deque

sys.setrecursionlimit(10**7)
inf = 10**20
mod = 10**9 + 7

DR = [1, -1, 0, 0]
DC = [0, 0, 1, -1]

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()

G = []

def dfs(n, string, next_usable):
    if n == 0:
        G.append(string)
        return
    for char in next_usable:
        new_string = string + char
        if char == next_usable[-1]:
            added_char = chr(ord(char) + 1)
            next_usable += added_char
        dfs(n-1, new_string, next_usable)

def main():
    N = I()
    string = 'a'
    dfs(N, '', 'a')
    for string in G:
        print(string)


main()
Buggy code:
n = int(input())

az = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

def norm(n, in_list):
	out_list = []
	for l in in_list:
		for i in range(len(set(l))+1):
			new = l + az[i]
      		out_list.append(new)
	return out_list

line = ["a"]

for _ in range(N-1):
  line = norm(1,line)
  
for l in line:
  print(l)


Fixed code:
N = int(input())
az = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
def norm(n, in_list):
	out_list = []
	for line in in_list:
		for i in range(len(set(line))+1):
			new_line = line + az[i]
			out_list.append(new_line)
	return out_list
init_line = ['a']
for _ in range(N-1):
	init_line = norm(1, init_line)
for line in init_line:
	print(line)
Buggy code:
n = int(input())

strings = ["a"]

for i in range(n-1):
    newstrings = []
    for s in strings:
        mx = ord('a')
        for char in s:
            mx = max(mx, ord(char))
        
        for c in range(ord('a'),mx+2):
            newstrings.append(s+chr(c))
    
    strings = newstrings

print(strings)

Fixed code:
n = int(input())

strings = ["a"]

for i in range(n-1):
    newstrings = []
    for s in strings:
        mx = ord('a')
        for char in s:
            mx = max(mx, ord(char))
        
        for c in range(ord('a'),mx+2):
            newstrings.append(s+chr(c))
    
    strings = newstrings

for s in strings:
    print(s)
Buggy code:
n=int(input())
ans=[]
def rec(i,s):
    if i == n:
        print(s)
        return
    else:
        for j in range(len(set(s)) + 1):
            rec(i+1,s+chr(old("a")+j))
rec(1,"a")

Fixed code:
n=int(input())
ans=[]
def rec(i,s):
    if i == n:
        print(s)
        return
    else:
        for j in range(len(set(s)) + 1):
            rec(i+1,s+chr(ord("a")+j))
rec(1,"a")
Buggy code:
n=int(input())
patterns = ["a"]
for _ in range(n-1):
    last_patterns = patterns.copy()
    patterns = []
    for string in last_patterns:
        useful_str = alpha[:len(set(string))+1]
        for str_ in useful_str:
            patterns.append(string + str_)

for pat in patterns:
    print(pat)

Fixed code:
alpha = "abcdefghij"
n=int(input())
patterns = ["a"]
for _ in range(n-1):
    last_patterns = patterns.copy()
    patterns = []
    for string in last_patterns:
        useful_str = alpha[:len(set(string))+1]
        for str_ in useful_str:
            patterns.append(string + str_)

for pat in patterns:
    print(pat)
Buggy code:
N=int(input())
A=["a"]
S="abcdefghijklmn"
for i in range(N-1):
    B=[]
    for a in A:
        for s in S[:len(set(a))+1]:
            B.append(a+s)
print("\n".join(B))

Fixed code:
N=int(input())
A=["a"]
S="abcdefghijklmn"
for i in range(N-1):
    B=[]
    for a in A:
        for s in S[:len(set(a))+1]:
            B.append(a+s)
    A=B[::]
print("\n".join(A))
Buggy code:
n = int(input())

tmp_list = list('a' * n)
num_list = [97] * n
target = n - 1
tmp_target=n-1
while tmp_target>0:
    print("".join(list(map(chr, num_list))))
    if num_list[target-1] >= num_list[target]:
        num_list[target] += 1
    else:
        num_list[target]=97
        tmp_target=target-1
        while tmp_target>0:
            if num_list[tmp_target-1] >=num_list[tmp_target]:
                num_list[tmp_target]+=1
                break
            else:
                num_list[tmp_target]=97
                tmp_target-=1


Fixed code:
n = int(input())
num_list = [97] * n
target = n - 1
tmp_target = n - 1
max_num = 97
if n==1:
    print('a')
while tmp_target > 0:
    print("".join(list(map(chr, num_list))))
    if max(num_list[0:target:]) >= num_list[target]:
        num_list[target] += 1
    else:
        num_list[target] = 97
        tmp_target = target - 1
        while tmp_target > 0:
            if max(num_list[0:tmp_target:]) >= num_list[tmp_target]:
                num_list[tmp_target] += 1
                break
            else:
                num_list[tmp_target] = 97
                tmp_target -= 1
Buggy code:
def num_to_str(n):
    return chr(97 + n)

def str_to_num(s):
    return ord(s) - 97

def dfs(s,m,n,N,ans):
    if n == N:
        ans.append(s)
        return
    for i in range(m+2):
        dfs(s+num_to_str(i),max(m,i),n+1,N,ans)

def main():
    N = int(input())
    ans = []
    dfs('a',0,1,N,ans)
    ans.sort()
    print(ans)


if __name__ == "__main__":
    main()


Fixed code:
def num_to_str(n):
    return chr(97 + n)

def str_to_num(s):
    return ord(s) - 97

def dfs(s,m,n,N,ans):
    if n == N:
        ans.append(s)
        return
    for i in range(m+2):
        dfs(s+num_to_str(i),max(m,i),n+1,N,ans)

def main():
    N = int(input())
    ans = []
    dfs('a',0,1,N,ans)
    ans.sort()
    for a in ans:
        print(a)


if __name__ == "__main__":
    main()
Buggy code:
n = int(input())

def dfs(s, mx):
    if len(s) == n:
        print(s)
    else:
        for c in [chr(ord('a') + i) for i in range(ord(mx) - ord('a') + 1)]:
            dfs(s + c, chr(ord(mx) + 1) if c == mx else mx)

dfx('', 'a')

Fixed code:
n = int(input())

def dfs(s, mx):
    if len(s) == n:
        print(s)
    else:
        for c in [chr(ord('a') + i) for i in range(ord(mx) - ord('a') + 1)]:
            dfs(s + c, chr(ord(mx) + 1) if c == mx else mx)

dfs('', 'a')
Buggy code:
import collections


def main():
    n = int(input())
    # if n == 1:
    #     print("a")
    # for i in range(2**(n-1)):
    #     bin_str = "0" + format(i, f'0{n-1}b')
    #     print(bin_str.replace("0", "a").replace("1", "b"))

    ret = [[] for _ in range(10)]
    ret[0] = ["a"]

    alp = "abcdefghijklmnopqrstuvwxyz"

    if n == 1:
        print(ret[n-1])
        return

    ind = 1
    while ind < n:
        tmp_len = len(ret[ind-1])
        for j, _r in enumerate(ret[ind-1]):
            alphabet_num = len(collections.Counter(_r))
            for k in range(alphabet_num+1):
                ret[ind].append(_r+alp[k])
        ind += 1

    print(ret[n-1])
    return


if __name__ == '__main__':
    main()


Fixed code:
import collections


def main():
    n = int(input())
    # if n == 1:
    #     print("a")
    # for i in range(2**(n-1)):
    #     bin_str = "0" + format(i, f'0{n-1}b')
    #     print(bin_str.replace("0", "a").replace("1", "b"))

    ret = [[] for _ in range(10)]
    ret[0] = ["a"]

    alp = "abcdefghijklmnopqrstuvwxyz"

    if n == 1:
        print(ret[n-1][0])
        return

    ind = 1
    while ind < n:
        tmp_len = len(ret[ind-1])
        for j, _r in enumerate(ret[ind-1]):
            alphabet_num = len(collections.Counter(_r))
            for k in range(alphabet_num+1):
                ret[ind].append(_r+alp[k])
        ind += 1


    for r in ret[n-1]:
        print(r)
    return


if __name__ == '__main__':
    main()
Buggy code:
std=[]
n=int(input())
cmb=[[] for i in range(n)]
cmb[0].append("a")
tmp=[[] for i in range(n)]
if n==1:
	print("a")
for i in range(1,n):
	for j in range(len(cmb)):
		for s in cmb[j]:
			for k in range(0,j+1):
				tmp[j].append(s+chr(ord("a")+k))
			tmp[j+1].append(s+chr(ord("a")+k+1))
	cmb=tmp
	tmp=[[] for i in range(n)]
lst=[]
for i in range(len(cmb)):
	for std in cmb[i]:
		lst.append(std)
lst.sort()
for i in range(len(lst)):
	print(lst[i])

Fixed code:
std=[]
n=int(input())
cmb=[[] for i in range(n)]
cmb[0].append("a")
tmp=[[] for i in range(n)]
for i in range(1,n):
	for j in range(len(cmb)):
		for s in cmb[j]:
			for k in range(0,j+1):
				tmp[j].append(s+chr(ord("a")+k))
			tmp[j+1].append(s+chr(ord("a")+k+1))
	#print(cmb)
	cmb=tmp
	tmp=[[] for i in range(n)]
lst=[]
for i in range(len(cmb)):
	for std in cmb[i]:
		lst.append(std)
lst.sort()
for i in range(len(lst)):
	print(lst[i])
Buggy code:
# coding: utf-8
N = int(input())

arrays = list("abcdefghij")
pat_dic = {i:arrays[i] for i in range(N)}
par_patterns = list(range(10))

patterns = par_patterns[:N]
def next_search(arr,N):
    tmp = arr.copy()
    if len(tmp) == N:
        print(''.join([pat_dic[tmp[i]] for i in range(N)]))
        return None
    for st in patterns:
        if max([0]+tmp)+1 < st:
            continue
        tmp.append(st)
        if tmp[0] != 0:
            continue

        next_search(tmp, N)
        tmp = arr.copy()

Fixed code:
# coding: utf-8
N = int(input())

arrays = list("abcdefghij")
pat_dic = {i:arrays[i] for i in range(N)}
par_patterns = list(range(10))

patterns = par_patterns[:N]
def next_search(arr,N):
    tmp = arr.copy()
    if len(tmp) == N:
        print(''.join([pat_dic[tmp[i]] for i in range(N)]))
        return None
    for st in patterns:
        if max([0]+tmp)+1 < st:
            continue
        tmp.append(st)
        if tmp[0] != 0:
            continue

        next_search(tmp, N)
        tmp = arr.copy()

next_search([], N)
Buggy code:
n = int(input())
s = [[] for i in range(n+1)]
s[1].append('a')
ans_s = []
for num in range(1,n):
    for st in s[num]:
        for add in range(97, max(map(ord,st))+2):
            s[num+1].append(st + chr(add))
print(s[n])

Fixed code:
n = int(input())
s = [[] for i in range(n+1)]
s[1].append('a')
ans_s = []
for num in range(1,n):
    for st in s[num]:
        for add in range(97, max(map(ord,st))+2):
            s[num+1].append(st + chr(add))
for sw in s[n]:
    print(sw)
Buggy code:
# -*- coding: utf-8 -*-
N=int(input())

l0=['a']
l1=[]
li=[0]
li1=[]
alp=[chr(i) for i in range(97, 97+26)]

for i in range(1,N):
    for j, l in enumerate(l0):
        ind=0
        while ind<=li[j]+1:
            l1.append(l+alp[ind])
            if ind==li[j]+1: li1.append(li[j]+1)
            else: li1.append(li[j])
            ind+=1
    l0=l1.copy()
    l1=[]
    li=li1.copy()
    li1=[]

print(l0)
        

Fixed code:
# -*- coding: utf-8 -*-
N=int(input())

l0=['a']
l1=[]
li=[0]
li1=[]
alp=[chr(i) for i in range(97, 97+26)]

for i in range(1,N):
    for j, l in enumerate(l0):
        ind=0
        while ind<=li[j]+1:
            l1.append(l+alp[ind])
            if ind==li[j]+1: li1.append(li[j]+1)
            else: li1.append(li[j])
            ind+=1
    l0=l1.copy()
    l1=[]
    li=li1.copy()
    li1=[]

for l in l0:
    print(l)
Buggy code:
n = int(input())

def dfs(s, mx):
    if len(s) == n:
        print(s)
    else:
        for i in range(0, mx +1):
            c = chr(ord('a')+i)
            dfs(s+c, mx +1) if i == mx else dfs(s+c, mx)

df('', 0)

Fixed code:
n = int(input())

def dfs(s, mx):
    if len(s) == n:
        print(s)
    else:
        for i in range(0, mx +1):
            c = chr(ord('a')+i)
            dfs(s+c, mx +1) if i == mx else dfs(s+c, mx)

dfs('', 0)
Buggy code:
N = input()
mojis = ["a","b","c","d","e","f","g","h","i","j"]
def append_m(moji):
    arr = []
    for i in mojis[:len(set(moji))+1]:
        arr.append(moji+i)
    return arr
arr = ["a"]
for i in range(N-1):
    tmp = []
    for j in arr:
        tmp += append_m(j)
    arr = tmp
for i in arr:
    print(i)

Fixed code:
N = int(input())
mojis = ["a","b","c","d","e","f","g","h","i","j"]
def append_m(moji):
    arr = []
    for i in mojis[:len(set(moji))+1]:
        arr.append(moji+i)
    return arr

arr = ["a"]
for i in range(N-1):
    tmp = []
    for j in arr:
        tmp += append_m(j)
    arr = tmp
for i in arr:
    print(i)
Buggy code:

import numpy as np
from functools import *
import sys
sys.setrecursionlimit(100000)
input = sys.stdin.readline




def acinput():
    return list(map(int, input().split(" ")))


def II():
    return int(input())

directions=np.array([[1,0],[0,1],[-1,0],[0,-1]])
directions = list(map(np.array, directions))

mod = 10**9+7


def factorial(n):
    fact = 1
    for integer in range(1, n + 1):
        fact *= integer
    return fact


ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz'
 
def search(seq,k,n):
    global N
    
    if k==N+1:

        res=[ascii_lowercase[s-1] for s in seq[1:]]
        print("".join(res))
        return 
    
    seq[k]=n
    search(seq,k+1,n+1)
    
    for l in range(1,n):
        seq[k] = l
        search(seq, k+1,n)
    

N=int(input())
seq=[-1]*(N+1)
seq[1]=1
search(seq,2,2)


Fixed code:

import numpy as np
from functools import *
import sys
sys.setrecursionlimit(100000)
input = sys.stdin.readline




def acinput():
    return list(map(int, input().split(" ")))


def II():
    return int(input())

directions=np.array([[1,0],[0,1],[-1,0],[0,-1]])
directions = list(map(np.array, directions))

mod = 10**9+7


def factorial(n):
    fact = 1
    for integer in range(1, n + 1):
        fact *= integer
    return fact


ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz'

res=[]
def search(seq,k,n):
    global N
    
    if k==N+1:

        tmp=[ascii_lowercase[s-1] for s in seq[1:]]
        res.append("".join(tmp))
        return 
    
    seq[k]=n
    search(seq,k+1,n+1)
    
    for l in range(1,n):
        seq[k] = l
        search(seq, k+1,n)
    

N=int(input())
seq=[-1]*(N+1)
seq[1]=1
search(seq,2,2)


res=sorted(res)

for rr in res:
    print(rr)
Buggy code:
n = int(input())

alp = [chr(v) for v in range(ord("a"), ord("z") + 1)]

def bitcount(v):
    cnt = 0
    for i in range(n):
        cnt += bool(v & (1 << i))
    return cnt

results = []
def f(i=0, j=0, s="", state=0):
    if i == n:
        if bitcount(state + 1) == 1:
            results.append(s)
        return
    for j in range(i + 1):
        f(i + 1, j, s + alp[j], state | (1 << j))
f()
print(*results, sep="\n")


Fixed code:
n = int(input())

alp = [chr(v) for v in range(ord("a"), ord("z") + 1)]

def bitcount(v):
    cnt = 0
    for i in range(n + 1):
        cnt += bool(v & (1 << i))
    return cnt

results = []
def f(i=0, s=""):
    if len(s) == n:
        results.append(s)
        return

    for j in range(i + 1):
        if i != j:
            f(i, s + alp[j])
    f(i + 1, s + alp[i])
f()
print(*results, sep="\n")
Buggy code:
from collections import deque

N = int(input())

queue = deque()
queue.append((0,)
while queue:
    s = queue.popleft()
    if len(s) == N:
        print(''.join('abcdefghij'[i] for i in s))
        continue
    for i in range(max(s) + 2):
        queue.append(s + (i,))

Fixed code:
from collections import deque

N = int(input())

queue = deque()
queue.append((0,))
while queue:
    s = queue.popleft()
    if len(s) == N:
        print(''.join('abcdefghij'[i] for i in s))
        continue
    for i in range(max(s) + 2):
        queue.append(s + (i,))
Buggy code:
from collections import deque
N=int(input())
X=[chr(i+97) for i in range(N)]
q=deque(["a"])
while(len(q)>0):
    r=q.popleft()
    k=len(set(r))
    for i in range(k+1):
        p=r+X[i]
        if len(p)==N:
            print(p)
        else:
            q.append(p)


Fixed code:
from collections import deque
N=int(input())
if N==1:
    print("a")
    exit()
X=[chr(i+97) for i in range(N)]
q=deque(["a"])
while(len(q)>0):
    r=q.popleft()
    k=len(set(r))
    for i in range(k+1):
        p=r+X[i]
        if len(p)==N:
            print(p)
        else:
            q.append(p)
Buggy code:
def DFS(s, mx):
    if len(s) == N:
        print(s)
        return
    c = 'a'
    while c <= chr(ord(mx)+1):
        t = s + c
        DFS(t, chr(max(ord(c), ord(mx))))
        c = chr(ord(c) + 1)
DFS("", chr(ord('a')-1))

Fixed code:
N = int(input())
def DFS(s, mx):
    if len(s) == N:
        print(s)
        return
    c = 'a'
    while c <= chr(ord(mx)+1):
        t = s + c
        DFS(t, chr(max(ord(c), ord(mx))))
        c = chr(ord(c) + 1)
DFS("", chr(ord('a')-1))
Buggy code:
n = int(input())

def dfs(s,mx):
    if len(s)==n:
        print(s)
        return None
    for i in range(ord('a'),(mx+1)+1):
        dfs(s+chr(i),max(mx,i))
dfs('',ord('a'))

Fixed code:
n = int(input())

def dfs(s,mx):
    if len(s)==n:
        print(s)
        return None
    for i in range(ord('a'),mx+1+1):
        dfs(s+chr(i),max(mx,i))
dfs('',ord('a')-1)
Buggy code:
import string
n = int(input())
cs = string.ascii_lowercase
cm = {cs[i]:i for i in range(len(cs))}
t = 1
def rec(st):
    global t
    if (len(st) >= n):
        print(t, ":", st)
        t += 1
        return 0
    k = max(cm[st[i]]+1 for i in range(len(st)))
    for c in cs[: k + 1]:
        rec(st+c)
    
    
rec('a')

Fixed code:
import string
n = int(input())
cs = string.ascii_lowercase
cm = {cs[i]:i for i in range(len(cs))}
t = 1
def rec(st):
    global t
    if (len(st) >= n):
        print(st)
        t += 1
        return 0
    k = max(cm[st[i]]+1 for i in range(len(st)))
    for c in cs[: k + 1]:
        rec(st+c)
    
    
rec('a')
Buggy code:
mport sys
sys.setrecursionlimit(10 ** 7)
from functools import lru_cache

n = int(input())
ans = []

if n == 1:
    print('a')
    exit()

@lru_cache(None)
def rec(before, depth, MAX):
    for i in range(MAX-ord('a') +2):
        tmp = before + chr(ord('a') + i)
        if len(tmp) >= n:
            ans.append(tmp)
        else:
            MAX = max(MAX, ord(tmp[-1]) )
            rec(tmp, depth+1, MAX)


rec('a',1, ord('a'))

ans.sort()

print(*ans, sep ='\n')


Fixed code:
import sys
sys.setrecursionlimit(10 ** 7)
from functools import lru_cache

n = int(input())
ans = []

if n == 1:
    print('a')
    exit()

@lru_cache(None)
def rec(before, depth, MAX):
    for i in range(MAX-ord('a') +2):
        tmp = before + chr(ord('a') + i)
        if len(tmp) >= n:
            ans.append(tmp)
        else:
            MAX = max(MAX, ord(tmp[-1]) )
            rec(tmp, depth+1, MAX)


rec('a',1, ord('a'))

ans.sort()

print(*ans, sep ='\n')
Buggy code:
from string import ascii_lowercase as alph

def gen_pattern(N, pre=""):
  for c in alp[:(ord(max(pre or "\x60"))-0x5f]:
    pattern = pre+c
    if len(pattern) == N:
      yield pattern
    else:
      yield from gen_pattern(N, pattern)

for pattern in gen_pattern(int(input())):
  print(pattern)


Fixed code:
from string import ascii_lowercase as alph

def gen_pattern(N, pre=""):
  for c in alph[:ord(max(pre or "\x60"))-0x5f]:
    pattern = pre+c
    if len(pattern) == N:
      yield pattern
    else:
      yield from gen_pattern(N, pattern)

for pattern in gen_pattern(int(input())):
  print(pattern)
Buggy code:
from string import ascii_lowercase as alph

def gen_pattern(N, pre="", m=-1):
  for i, c in enumerate(alph[:m+2]):
    pat = pre+c
    if len(pattern) == N:
      yield pattern
    else:
      yield from gen_pattern(N, pat, max(i,m))

for pattern in gen_pattern(int(input())):
  print(pattern)


Fixed code:
from string import ascii_lowercase as alph

def gen_pattern(N, pre="", m=-1):
  for i, c in enumerate(alph[:m+2]):
    pat = pre+c
    if len(pat) == N:
      yield pat
    else:
      yield from gen_pattern(N, pat, max(i,m))

for pattern in gen_pattern(int(input())):
  print(pattern)
Buggy code:
n=int(input())
dic={0:'a',1:'b',2:'c',3:'d',4:'e',5:'f',6:'g',7:'h',8:'i',9:'j'}
ans=[['a',1]]
for i in range(1,n):
  tmp=[]
  for prev,val in ans:
    for j in range(val+1):
      if j!=val:
        tmp.append([prev+dic[j],val])
      else:
        tmp.append([prev+dic[j],val+1])
  ans=tmp
ans=sorted(ans,key=lambda x:x[0])
print(len(ans))
for i in range(len(ans)):
  print(ans[i][0])

Fixed code:
n=int(input())
dic={0:'a',1:'b',2:'c',3:'d',4:'e',5:'f',6:'g',7:'h',8:'i',9:'j'}
ans=[['a',1]]
for i in range(1,n):
  tmp=[]
  for prev,val in ans:
    for j in range(val+1):
      if j!=val:
        tmp.append([prev+dic[j],val])
      else:
        tmp.append([prev+dic[j],val+1])
  ans=tmp
ans=sorted(ans,key=lambda x:x[0])
for i in range(len(ans)):
  print(ans[i][0])
Buggy code:
n = int(input())

tank = []
res = ["a"]

for le in range(1,n):
    tank = res
    res = []
    for i in range(len(tank)):
        tmp = "a"
        for j in range(le):
            res.append(tank[i] + tank[i][j])
            if tank[i][j] > tmp:
                tmp = tank[i][j]
        res.append(tank[i] + chr(ord(tmp)+1))
    res = list(set(res))

print(*res)

Fixed code:
n = int(input())

tank = []
res = ["a"]

for le in range(1,n):
    tank = res
    res = []
    for i in range(len(tank)):
        tmp = "a"
        for j in range(le):
            res.append(tank[i] + tank[i][j])
            if tank[i][j] > tmp:
                tmp = tank[i][j]
        res.append(tank[i] + chr(ord(tmp)+1))
    res = list(set(res))
res.sort()

for e in res:
    print(e)
Buggy code:
from itertools import product, combinations_with_replacement
N=int(input())
s="abcdefghij"

def get_gen(a, N):
  for c in s[:s.index(max(a))+2]:
    t = a+c
    if len(t) == N:
      print(t)
    else:
      get_gen(t,N)
get_gen("a", N)

Fixed code:
from itertools import product, combinations_with_replacement
N=int(input())
s="abcdefghij"
 
def get_gen(a, N):
  for c in s[:s.index(max(a))+2 if a else 1]:
    t = a+c
    if len(t) == N:
      print(t)
    else:
      get_gen(t,N)

get_gen("", N)
Buggy code:
import math
import collections
import fractions
import itertools
import functools
import operator
import bisect

def solve():
    n = int(input())
    ans = ["a"]
    alt = [chr(ord("a") + i) for i in range(n)]
    for i in range(n-1):
        ans = [s+x for s in ans for x in alt [0:len(set(ans))+1]]
    for i in ans:
        print(ans)
    return 0

if __name__ == "__main__":
    solve()

Fixed code:
import math
import collections
import fractions
import itertools
import functools
import operator
import bisect

def solve():
    n = int(input())
    sushi = ["a"]
    alt = [chr(ord("a") + i) for i in range(n)]
    for i in range(n-1):
        sushi = [ans + x for ans in sushi for x in alt[:len(set(ans)) + 1]]
    for i in sushi:
        print(i)
    return 0

if __name__ == "__main__":
    solve()