qyliang/CodeNanoFix huggingface dataset:
Buggy code:
N = int(input())
ans = ''
while N:
    if N%(-2) == 0:
        N = N//-2
        ans = '0' + ans
    else:
        N = (N-1)//-2
        ans = '1' + ans
print(ans)

Fixed code:
N = int(input())
ans = ''
if N == 0:
    print('0')
while N:
    if N%(-2) == 0:
        N = N//-2
        ans = '0' + ans
    else:
        N = (N-1)//-2
        ans = '1' + ans
print(ans)
Buggy code:
N=int(input())

x=[]
if N != 0:
	flag = N // abs(N)
N=abs(N)
while N != 0:
	x.insert(0,N % 2 * flag )
	N //= 2
	flag *= -1
x.insert(0,0)
x.insert(0,0)

# 2 = (-1)*(-2) = (-2+1)*(-2) = (-2)^2+(-2)
for i in range(len(x))[::-1]:
	if x[i] == -1:
		x[i] = 1
		x[i-1] += 1
	if x[i] == 2:
		x[i] = 0
		x[i-1] += 1
		x[i-2] += 1

if x[0]==1:
	print(1,end="")
elif len(x)==1:
	print(0)
for i in range(1,len(x)):
	print(x[i],end="")
"""
print()
check=0
count=1
for i in range(len(x))[::-1]:
	check +=  x[i] * count
	count *= -2
print(check)
"""

Fixed code:
N=int(input())

x=[]
if N != 0:
	flag = N // abs(N)
N=abs(N)
while N != 0:
	x.insert(0,N % 2 * flag )
	N //= 2
	flag *= -1
x.insert(0,0)
x.insert(0,0)

# 2 = (-1)*(-2) = (-2+1)*(-2) = (-2)^2+(-2)
for i in range(len(x))[::-1]:
	if x[i] == -1:
		x[i] = 1
		x[i-1] += 1
	if x[i] == 2:
		x[i] = 0
		x[i-1] += 1
		x[i-2] += 1

flag=0
for i in range(len(x)):
	if x[i] == 1 or i == len(x)-1:
		flag=1
	if flag == 1:
		print(x[i],end="")
"""
print()
check=0
count=1
for i in range(len(x))[::-1]:
	check +=  x[i] * count
	count *= -2
print(check)
"""
Buggy code:
N=int(input())
res=""
while N!=0:
	if N%2==0:
		res+="0"
	else:
		N-=1
		res+="1"
	print(N)
	N//=-2
if len(res)==0:
	res="0"
print(res[::-1])


Fixed code:
N=int(input())
res=""
while N!=0:
	if N%2==0:
		res+="0"
	else:
		N-=1
		res+="1"
	#print(N)
	N//=-2
if len(res)==0:
	res="0"
print(res[::-1])
Buggy code:
n=-int(input())
a=""
while n:
    a+=str(n%2)
    n//=-2
print(a[::-1] if n else 0)

Fixed code:
n=-int(input())
a=""
while n:
    a+=str(n%2)
    n//=-2
print(a[::-1] if a else 0)
Buggy code:
N = int(input())
str = ''

while(N != 0):
    if N % 2:
        N -= 1
        N //= -2
        str += '1'
    else:
        N //= -2
        str += '0'

print(str[::-1])


Fixed code:
N = int(input())
str = ''

while(N != 0):
    if N % 2:
        N -= 1
        N //= -2
        str += '1'
    else:
        N //= -2
        str += '0'

if str == '':
    print(0)
else:
    print(str[::-1])
Buggy code:
N =int(input().strip())

target = N
output_str = ""

while target != 0:
    if target % 2 == 1:
        output_str = "1" + output_str
        target = (target - 1) / (-2)
    else:
        output_str = "0" + output_str
        target = (target) / (-2)

print(output_str)

Fixed code:
N =int(input().strip())

target = N
output_str = ""

while target != 0:
    if target % 2 == 1:
        output_str = "1" + output_str
        target = (target - 1) / (-2)
    else:
        output_str = "0" + output_str
        target = (target) / (-2)

if output_str != "" :
    print(output_str)
else:
    print("0")
Buggy code:
n = int(input())
list1 = []

chinpo = 1

while True:
    if n==0:
        break
    if n%2 != 0:
        n -=1
        list1.append(1)
    else:
        list1.append(0)
    n /= -2

list1.reverse()
print("".join(map(str,list1)))

Fixed code:
n = int(input())
list1 = []

chinpo = 1

if n == 0:
    print(0)
    exit()

while True:
    if n==0:
        break
    if n%2 != 0:
        n -=1
        list1.append(1)
    else:
        list1.append(0)
    n /= -2

list1.reverse()
print("".join(map(str,list1)))
Buggy code:
n = int(input())
def divminus2(n):
    if n%2 == 1:
        q = n // -2 + 1
        r = abs(n % 2)
    else:
        q = n // -2
        r = 0
    return q,r

ans_list = []
while n != 0:
    q,r = divminus2(n)
    n = q
    ans_list.append(str(r))

ans_list.reverse()
print("".join(ans_list))


Fixed code:
n = int(input())
def divminus2(n):
    if n%2 == 1:
        q = n // -2 + 1
        r = abs(n % 2)
    else:
        q = n // -2
        r = 0
    return q,r

ans_list = []
while n != 0:
    q,r = divminus2(n)
    n = q
    ans_list.append(str(r))

ans_list.reverse()
if ans_list == []:
    print("0")
else:
    print("".join(ans_list))
Buggy code:
import sys
import math
y = int(input().split()[0])
result = ""
i = 0
while True:
    print(i)
    z = (-2) ** (i+1)
    x = y % z
    print(x)
    if x != 0:
        y = y + x
        result = "1" + result
    else:
        result = "0" + result
    if y == 0:
        break
    i = i + 1
print(result)

Fixed code:
import sys
import math
y = int(input().split()[0])
result = ""
i = 0
while True:
    z = (-2) ** (i+1)
    x = y % z
    if x != 0:
        y = y + x
        result = "1" + result
    else:
        result = "0" + result
    if y == 0:
        break
    i = i + 1
print(result)
Buggy code:
n = int(input())
if n == 0:
	 print ("0")
out = []
while n != 0:
	 n, rem = divmod(n, -2)
	 if rem < 0:
	 	 n += 1
	 	 rem -= ^2
	 out.append(rem)
print ("".join(map(str, out[::-1])))

Fixed code:
n = int(input())
if n == 0:
	 print ("0")
out = []
while n != 0:
	 n, rem = divmod(n, -2)
	 if rem < 0:
	 	 n += 1
	 	 rem -= -2
	 out.append(rem)
print ("".join(map(str, out[::-1])))
Buggy code:
n = int(input())

ans = ""

while n != 0:
    if n % 2 == 1:
        ans += "1"
        n = n - 1
        n //= -2
    else:
        ans += "0"
        n //= -2

print(ans[::-1] if n != 0 else 0)

Fixed code:
n = int(input())
N = n

ans = ""

while n != 0:
    if n % 2 == 1:
        ans += "1"
        n = n - 1
        n //= -2
    else:
        ans += "0"
        n //= -2

print(ans[::-1] if N != 0 else 0)
Buggy code:
N = int(input())

def nega_binary(num):
	res = []
	while num != 0:
		remainder = abs(num) % 2
		res.append(str(remainder))
		if num < 0 and remainder:
			num -= 1
		num = int(num / -2)

	return ''.join(reversed(res))

print(nega_binary(N))

Fixed code:
N = int(input())

def nega_binary(num):
    if num == 0:
        return 0
    res = []
    while num != 0:
        remainder = abs(num) % 2
        res.append(str(remainder))
        if num < 0 and remainder:
            num -= 1
        num = int(num / -2)
    return ''.join(reversed(res))

print(nega_binary(N))
Buggy code:
# coding: utf-8

def get_ans():
    n = int(input().rstrip())
    dv = 1
    bit_list = []
    while n != 0:
        tmp = n % (dv*2)
        if tmp == 0:
            bit_list.append("0")
        else:
            bit_list.append("1")
        n -= tmp
        dv *= -2
    return "".join(reversed(bit_list))


print(get_ans())


Fixed code:
# coding: utf-8

def get_ans():
    n = int(input().rstrip())
    if n == 0:
        return "0"
    dv = 1
    bit_list = []
    while n != 0:
        tmp = n % (dv*2)
        if tmp == 0:
            bit_list.append("0")
        else:
            bit_list.append("1")
        n -= tmp
        dv *= -2
    return "".join(reversed(bit_list))


print(get_ans())
Buggy code:
N = int(input())

ans = ""
while N != 0:
    b = N % 2
    ans += str(b)
    N = (N - b) // -2

print(ans[::-1])


Fixed code:
N = int(input())

ans = ""
if N == 0:
    ans = "0"
else:
    while N != 0:
        b = N % 2
        ans += str(b)
        N = (N - b) // -2

print(ans[::-1])
Buggy code:
N = int(input())
ans = ""
if N == 0:
    ans = "0"
while N != 0:
    if N % 2 != 0:
        N -= 1
        ans = "1" + ans
    else:
        ans = "0" + ans
        N //= -2

print(int(ans))

Fixed code:
N = int(input())
ans = ""
if N == 0:
    ans = "0"
while N != 0:
    if N % 2 != 0:
        N -= 1
        ans = "1" + ans
    else:
        ans = "0" + ans

    N //= -2

print(int(ans))
Buggy code:
N = int(input())

ans = []
N = -N
while N != 0:
    ans.append(N%2)
    N //= -2

ans.reverse()
print(*ans, sep="")


Fixed code:
N = int(input())

ans = []
N = -N
while N != 0:
    ans.append(N%2)
    N //= -2

if ans:
    ans.reverse()
    print(*ans, sep="")
else:
    print(0)
Buggy code:
n = int(input())
s = ''
while(n!=0):
    r = n % 2
    if r<0:
        r += 2
    n = (n-r) // (-2)
    s += str(r)
ans = s[::-1]
print(ans)

Fixed code:
n = int(input())
s = ''
if n==0:
  print(0)
  exit()
while(n!=0):
    r = n % 2
    if r<0:
        r += 2
    n = (n-r) // (-2)
    s += str(r)
ans = s[::-1]
print(ans)
Buggy code:
n = int(input())

i = 1
ans = ''
while n != 0:
  pi = pow(-1, i-1) * pow(2, i)
  if n % pi == pi // 2:
    ans += '1'
    n -= pi // 2
  else:
    ans += '0'
  i += 1
if n == 0:
  print(0)
else:
  print(ans[::-1])


Fixed code:
n = int(input())

if n == 0:
  print(0)
else:
  i = 1
  ans = ''
  while n != 0:
    pi = pow(-1, i-1) * pow(2, i)
    if n % pi == pi // 2:
      ans += '1'
      n -= pi // 2
    else:
      ans += '0'
    i += 1
  print(ans[::-1])
Buggy code:
N = int(input())

if N == 1:
    print('1')
if N == -1:
    print('11')
if N == -2:
    print('10')

m = 400
length = 0
for i in range(3, m):
    posneg = 1 if i % 2 == 1 else -1
    if posneg == 1 and 4**((i+1)/2 - 1) / 3 <= N and N <= 4**((i+1)/2) / 3:
        length = i
        break
    elif posneg == -1 and -(4)**((i+1)/2 - 1)/ 3 >= N and N >= -(4)**((i+1) /2) / 3:
        length = i
        break

ans = ''
for i in range(length, 2, -1):
    posneg = 1 if i % 2 == 1 else -1
    if posneg == 1:
        if 4**((i+1)/2 - 1) / 3 <= N and N <= 4**((i+1)/2) / 3:
            N -= 2**(i - 1)
            ans += '1'
        else:
            ans += '0'
    elif posneg == -1:
        if posneg == -1 and -(4)**((i+1)/2 - 1)/ 3 >= N and N >= -(4)**((i+1) /2) / 3:
            N += 2**(i - 1)
            ans += '1'
        else:
            ans += '0'

if N == 1:
    ans += '01'
if N == -1:
    ans += '11'
if N == -2:
    ans += '10'


print(ans)









Fixed code:
N = int(input())

if N ==0:
    print('0')
    exit()
if N == 1:
    print('1')
    exit()
if N == -1:
    print('11')
    exit()
if N == -2:
    print('10')
    exit()

m = 400
length = 0
for i in range(3, m):
    posneg = 1 if i % 2 == 1 else -1
    if posneg == 1 and 4**((i+1)/2 - 1) / 3 <= N and N <= 4**((i+1)/2) / 3:
        length = i
        break
    elif posneg == -1 and -(4)**((i+1)/2 - 1)/ 3 >= N and N >= -(4)**((i+1) /2) / 3:
        length = i
        break
ans = ''
for i in range(length, 2, -1):
    posneg = 1 if i % 2 == 1 else -1
    if posneg == 1:
        if 4**((i+1)/2 - 1) / 3 <= N and N <= 4**((i+1)/2) / 3:
            N -= 2**(i - 1)
            ans += '1'
        else:
            ans += '0'
    elif posneg == -1:
        if posneg == -1 and -(4)**((i+1)/2 - 1)/ 3 >= N and N >= -(4)**((i+1) /2) / 3:
            N += 2**(i - 1)
            ans += '1'
        else:
            ans += '0'

if N ==	0:
    ans += '00'
if N == 1:
    ans += '01'
if N == -1:
    ans += '11'
if N == -2:
    ans += '10'


print(ans)
Buggy code:
import sys
N = int(sys.stdin.readline())

def div(a):
    return -(a // 2), a % 2


res = []
while N < 0 or 2 <= N:
    N, a = div(N)
    print(N, a)
    res.append(a)
res.append(N)

print(''.join(map(str, reversed(res))))


Fixed code:
import sys
N = int(sys.stdin.readline())

def div(a):
    return -(a // 2), a % 2


res = []
while N < 0 or 2 <= N:
    N, a = div(N)
    res.append(a)
res.append(N)

print(''.join(map(str, reversed(res))))
Buggy code:
from itertools import product
def main():
    N = int(input())
    if N == 0:
        return 0
    l = set()
    while N != 0:
        if N > 0:
            r = plus(N)
            l.add(r)
            N -= pow(2, r)
        else:
            r = minus(N)
            l.add(r)
            N += pow(2, r)
    s = [0] * (max(l)+1)
    for i in range(max(l)+1):
        if i in l:
            print(i)
            s[i] = 1
    s.reverse()
    return ''.join(str(i) for i in s)

def plus(N):
    p = 0
    n = 0
    while True:
        p += pow(2, n)
        if p >= N:
            break
        n += 2
    return n
def minus(N):
    p = 0
    n = 1
    while True:
        p -= pow(2, n)
        if p <= N:
            break
        n += 2
    return n

print(main())


Fixed code:
def main():
    N = int(input())
    if N == 0:
        return 0
    l = set()
    while N != 0:
        if N > 0:
            r = plus(N)
            l.add(r)
            N -= pow(2, r)
        else:
            r = minus(N)
            l.add(r)
            N += pow(2, r)
    s = [0] * (max(l)+1)
    for i in range(max(l)+1):
        if i in l:
            s[i] = 1
    s.reverse()
    return ''.join(str(i) for i in s)
def plus(N):
    p = 0
    n = 0
    while True:
        p += pow(2, n)
        if p >= N:
            break
        n += 2
    return n
def minus(N):
    p = 0
    n = 1
    while True:
        p -= pow(2, n)
        if p <= N:
            break
        n += 2
    return n

print(main())
Buggy code:
import sys
from collections import deque

sys.setrecursionlimit(10 ** 6)


def input(): return sys.stdin.readline().rstrip()


N = int(input())
l = deque()
while N != 0:
    x = (-2) ** len(l)
    y = (-2) * x
    if abs(N) % abs(y) != 0:
        N -= x
        l.appendleft('1')
    else:
        l.appendleft('0')
print(0 if N == 0 else ''.join(l))

Fixed code:
import sys
from collections import deque

sys.setrecursionlimit(10 ** 6)


def input(): return sys.stdin.readline().rstrip()


N = int(input())
l = deque()
if N == 0:
    print(0)
else:
    while N != 0:
        x = (-2) ** len(l)
        y = (-2) * x
        if abs(N) % abs(y) != 0:
            N -= x
            l.appendleft('1')
        else:
            l.appendleft('0')
    print(''.join(l))
Buggy code:
N = int(input())

S = str()
count = 1
memo = 0
while a:
    amari = N%(2 ** count)
#    print ('amari', amari)
    if (amari- memo) == 2 ** (count-1):
        s = 1
    else:
        s = 0
    memo = memo + s * (-2) **(count-1)
#    print ('momo', memo)
    S = str(s) + S
    count += 1
    if memo == N:
        print (S)
        a = not a


Fixed code:
N = int(input())

S = str()
a = True
count = 1
memo = 0
while a:
    amari = N%(2 ** count)
#    print ('amari', amari)
    if (amari- memo) == 2 ** (count-1):
        s = 1
    else:
        s = 0
    memo = memo + s * (-2) **(count-1)
#    print ('momo', memo)
    S = str(s) + S
    count += 1
    if memo == N:
        print (S)
        a = not a
Buggy code:
a=int(input())
b=''
while a:
 b=str(a&1)+b
 a=-(a<<1)
print(b if b else 0)


Fixed code:
a=int(input())
b=''
while a:
 b=str(a&1)+b
 a=-(a>>1)
print(b if b else 0)
Buggy code:
import sys

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

if n==0:
    print(0)
    sys.exit()
    
while n!=0:
    if n%2 == 1:
        res.append(1)
        n = (n-1)/(-2)
    else:
        res.append(0)
        n = n/(-2)

reversed(res)

for i in res:
    print(i, end="")

Fixed code:
import sys

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

if n==0:
    print(0)
    sys.exit()
    
while n!=0:
    if n%2 == 1:
        res.append(1)
        n = (n-1)/(-2)
    else:
        res.append(0)
        n = n/(-2)


for i in reversed(res):
    print(i, end="")
Buggy code:
n = int(input())
ans = ''
while n!=0:
    r = n%2
    n = (n-r) // (-2)
    ans += str(r)
print(ans[::-1])

Fixed code:
n = int(input())
ans = ''
while n!=0:
    r = n%2
    n = (n-r) // (-2)
    ans += str(r)
print(ans[::-1] if ans else 0)
Buggy code:
import sys

n = int(sys.stdin.readline().rstrip())

def base_convert(n, b):
    res = ''
    while n:
        r = abs(n % b)
        res = str(r) + res
        n = (n - r) // b

    return int(res) if res else 0

def main():
    return base_convert(n, 3)

if __name__ == '__main__':
    ans = main()
    print(ans)

Fixed code:
import sys

n = int(sys.stdin.readline().rstrip())

def base_convert(n, b):
    res = ''
    while n:
        r = abs(n % b)
        res = str(r) + res
        n = (n - r) // b

    return int(res) if res else 0

def main():
    return base_convert(n, -2)

if __name__ == '__main__':
    ans = main()
    print(ans)
Buggy code:
N = int(input())
S = ""
if N == 1:
    print("1")
elif N == 0:
    print("0")
else:
    while N != 1:
        if abs(N)%2 == 1:
            N = (N-1)//(-2)
            S += "1"
        else:
            N = N//(-2)
            S += "0"
S += "1"
print(S[::-1])


Fixed code:
N = int(input())
S = ""
if N == 1:
    print("1")
elif N == 0:
    print("0")
else:
    while N != 1:
        if abs(N)%2 == 1:
            N = (N-1)//(-2)
            S += "1"
        else:
            N = N//(-2)
            S += "0"
    S += "1"
    print(S[::-1])
Buggy code:
N = int(input())
if N == 0:
    print(0)
else:
    li = []
    ind = 0
    while N != 0:
        if N % 2**(ind + 1) == 0:
            li.insert(0,0)
            ind += 1
        else:
            li.insert(0,1)
            N -= (-2)**(ind)
            ind += 1            
            x = ''.join([str(li[i]) for i in range(len(li))])
            print(x)

Fixed code:
N = int(input())
if N == 0:
    print(0)
else:
    li = []
    ind = 0
    while N != 0:
        if N % 2**(ind + 1) == 0:
            li.insert(0,0)
            ind += 1
        else:
            li.insert(0,1)
            N -= (-2)**(ind)
            ind += 1            
    x = ''.join([str(li[i]) for i in range(len(li))])
    print(x)
Buggy code:
n = int(input())
ans = []

while n != 0:
    if n % -2 == -1:
        n = n // -2 + 1
        ans.append('1')
    else:
        n = n // -2
        ans.append('0')
    
ans.reverse()

if n == 0:
    print('0')
else:
    print(''.join(ans))

Fixed code:
n = int(input())
ans = []

if n == 0:
    print('0')

else:
    while n != 0:
        if n % -2 == -1:
            n = n // -2 + 1
            ans.append('1')
        else:
            n = n // -2
            ans.append('0')
    
    ans.reverse()

    print(''.join(ans))
Buggy code:
n = int(input())
binary = []
flag = 0

if n == 0:
    print(0)
    flag = 1
    
while n != 0:
    if n % -2 != 0:
        binary.append('1')
        n = n // -2 + 1
    else:
        binary.append('0')
        n = n // -2
        
if flag == 0:
    print(''.join(binary))

Fixed code:
n = int(input())
binary = []
flag = 0

if n == 0:
    print(0)
    flag = 1
    
while n != 0:
    if n % -2 != 0:
        binary.append('1')
        n = n // -2 + 1
    else:
        binary.append('0')
        n = n // -2

binary.reverse()

if flag == 0:
    print(''.join(binary))
Buggy code:
N = int(input())
binarys = []
flag = 0

if N == 0:
    print(0)
    flag = 1
    
while N != 0:
    if N % -2 != 0:
        binarys.append('1')
        N = N // -2
    else:
        binarys.append('0')
        N = N // -2

binarys.reverse()

if flag == 0:
    print(''.join(binarys))

Fixed code:
N = int(input())
binarys = []
flag = 0

if N == 0:
    print(0)
    flag = 1
    
while N != 0:
    if N % -2 != 0:
        binarys.append('1')
        N = N // -2 + 1
    else:
        binarys.append('0')
        N = N // -2

binarys.reverse()

if flag == 0:
    print(''.join(binarys))
Buggy code:
N = int(input())
i = 0
ans = []
while N:
  if N%(2)**(i+1) > 0:
    ans.append(1)
    N -= (-2)**i
  else:
    ans.append(0)
  i += 1
ans.reverse()
print("".join(map(str,ans)))

Fixed code:
N = int(input())
i = 0
ans = []
if N == 0:
  print(0)
  exit()
while N:
  if N%(2)**(i+1) > 0:
    ans.append(1)
    N -= (-2)**i
  else:
    ans.append(0)
  i += 1
ans.reverse()
print("".join(map(str,ans)))
Buggy code:
N = int(input())
ans = N
result = []
while ans != 0:
    if(ans % 2 == 1):
        ans = (ans-1)/(-2)
        result.append(1)
    else:
        ans = ans/(-2)
        result.append(0)

result.reverse()
nishin = ''
for i in range(len(result)):
    nishin = nishin+str(result[i])
print(nishin)

Fixed code:
N = int(input())
ans = N
result = []
nishin = ''
if(N == 0):
    nishin = '0'
    print(nishin)
    exit()
while ans != 0:
    if(ans % 2 == 1):
        ans = (ans-1)/(-2)
        result.append(1)
    else:
        ans = ans/(-2)
        result.append(0)

result.reverse()
for i in range(len(result)):
    nishin = nishin+str(result[i])
print(nishin)
Buggy code:
import sys
stdin = sys.stdin
sys.setrecursionlimit(10**6)
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nn = lambda: list(stdin.readline().split())
ns = lambda: stdin.readline().rstrip()

n = ni()
a = 2
ans = ''

while n != 0:
    if n%a == 0:
        ans = '0' + ans
    else:
        ans = '1' + ans
        n-=(a//2)
    a*=(-2)

print(ans)

Fixed code:
import sys
stdin = sys.stdin
sys.setrecursionlimit(10**6)
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nn = lambda: list(stdin.readline().split())
ns = lambda: stdin.readline().rstrip()

n = ni()
a = 2
ans = ''

if n==0:
    print(0)
    exit()

while n != 0:
    if n%a == 0:
        ans = '0' + ans
    else:
        ans = '1' + ans
        n-=(a//2)
    a*=(-2)

print(ans)
Buggy code:
n=int(input())

kp=-10
km=10
k=0
while not(km<=n and n<=kp):
    k=k+1
    km=-int(2*(4**k-1)/(4-1))
    kp=int((4**k-1)/(4-1))
    print("n=",n,"k=",k,"km=",km,"kp=",kp)        
#print("n=",n,"n-km=",n-km)

n=n-km

v=""
for kk in range(k):
    np=n//4**(k-kk-1)
    n=n-np*4**(k-kk-1)
    if np==0:
        v=v+"10"
    elif np==1:
        v=v+"11"
    elif np==2:
        v=v+"00"
    elif np==3:
        v=v+"01"
#print("v=",v)

if len(v)>0 and v[0]=="0":
    v=v[1:]
if len(v)>0:
    print(v)
else:
    print(0)

Fixed code:
n=int(input())

kp=-10
km=10
k=0
while not(km<=n and n<=kp):
    k=k+1
    km=-int(2*(4**k-1)/(4-1))
    kp=int((4**k-1)/(4-1))
#    print("n=",n,"k=",k,"km=",km,"kp=",kp)        
#print("n=",n,"n-km=",n-km)

n=n-km

v=""
for kk in range(k):
    np=n//4**(k-kk-1)
    n=n-np*4**(k-kk-1)
    if np==0:
        v=v+"10"
    elif np==1:
        v=v+"11"
    elif np==2:
        v=v+"00"
    elif np==3:
        v=v+"01"
#print("v=",v)

if len(v)>0 and v[0]=="0":
    v=v[1:]
if len(v)>0:
    print(v)
else:
    print(0)
Buggy code:
def main():
    N = int(input())
    L = [(0, 1), (-2, 1)]
    for leng in range(2, 17):
        min_v = (-2*(4**(leng+(2-1)//2) - 1))//3
        max_v = (4**(leng+(2-1)//2) - 1)//3
        L.append((L[-1][0], max_v))
        L.append((min_v, max_v))
    # print(*L, sep='\n')
    S = [(0, 1)]
    for leng in range(1, 32):
        if leng & 1:
            S.append((L[leng][0], L[leng-1][0]-1))
        else:
            S.append((L[leng-1][1]+1, L[leng][1]))
    # print(*S, sep='\n')
    ans = ["0"] * 32
    cnt = 31
    for le, ri in S[::-1]:
        if ri < le:
            le, ri = ri, le
        if le <= N <= ri:
            ans[cnt] = "1"
            N -= (-2)**cnt
        cnt -= 1
    print(int("".join(ans[::-1])))


if __name__ == '__main__':
    main()


Fixed code:
def main():
    N = int(input())
    L = [(0, 1), (-2, 1)]
    for leng in range(2, 17):
        min_v = (-2*(4**(leng+(2-1)//2) - 1))//3
        max_v = (4**(leng+(2-1)//2) - 1)//3
        L.append((L[-1][0], max_v))
        L.append((min_v, max_v))
    # print(*L, sep='\n')
    S = [(1, 1)]
    for leng in range(1, 32):
        if leng & 1:
            S.append((L[leng][0], L[leng-1][0]-1))
        else:
            S.append((L[leng-1][1]+1, L[leng][1]))
    # print(*S, sep='\n')
    ans = ["0"] * 32
    cnt = 31
    for le, ri in S[::-1]:
        if ri < le:
            le, ri = ri, le
        if le <= N <= ri:
            ans[cnt] = "1"
            N -= (-2)**cnt
        cnt -= 1
    print(int("".join(ans[::-1])))


if __name__ == '__main__':
    main()
Buggy code:
N = int(input())

B = ""
i = 0
while N != 0:
  B = str(abs(N % (-2))) + B
  if i % 2 == 0:
    N = (N + (N % (-2))) // 2
  else:
    N = (N - (N % (-2))) // 2
  i += 1

print (B)


Fixed code:
N = int(input())

B = ""
i = 0
if N == 0:
  print (0)
else:
  while N != 0:
    B = str(abs(N % (-2))) + B
    if i % 2 == 0:
      N = (N + (N % (-2))) // 2
    else:
      N = (N - (N % (-2))) // 2
    i += 1
  print (B)
Buggy code:
n = int(input())
if n ==0:
  print(0)
s=''
while n !=0:
  if n%2==1:
    s="1"+
    n-=1
  else:
    s='0'+s
  n-=n//2
print(s)


Fixed code:
n = int(input())
if n ==0:
  print(0)
s=''
while n !=0:
  if n%2==1:
    s="1"+s
    n-=1
  else:
    s='0'+s
  n=-n//2
print(s)