Java 
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```java []
class Solution {
    public String baseNeg2(int n) {
        if(n==0 || n==1) return String.valueOf(n);
        if(n%2 == 0) return baseNeg2(n/-2) + "0";
        else return baseNeg2((n-1)/-2) + "1";
    }                                                   
}
```
['Java']