Given a number N, return a string consisting of "0"s and "1"s that represents its value in base -2 (negative two).
The returned string must have no leading zeroes, unless the string is "0".
Example 1:
Input: 2
Output: "110"
Explantion: (-2) ^ 2 + (-2) ^ 1 = 2
Example 2:
Input: 3
Output: "111"
Explantion: (-2) ^ 2 + (-2) ^ 1 + (-2) ^ 0 = 3
Example 3:
Input: 4
Output: "100"
Explantion: (-2) ^ 2 = 4
Note:
0 <= N <= 10^9
class Solution:
    def baseNeg2(self, N):
        res = []
        while N != 0:
            m = N %(-2)
            if m == -1:
                m = 1
            N = (N-m) // (-2)
            res.append(str(m))
            
        return ''.join(res[::-1]) or '0'
class Solution:
    def baseNeg2(self, N):
        res = []
        while N != 0:
            m = N %(-2)
            if m == -1:
                m = 1
            N = (N-m) // (-2)
            res.append(str(m))
            
        return ''.join(res[::-1]) or '0'