<p>Given an integer <code>n</code>, return <em>a binary string representing its representation in base</em> <code>-2</code>.</p>

<p><strong>Note</strong> that the returned string should not have leading zeros unless the string is <code>&quot;0&quot;</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> n = 2
<strong>Output:</strong> &quot;110&quot;
<strong>Explantion:</strong> (-2)<sup>2</sup> + (-2)<sup>1</sup> = 2
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> n = 3
<strong>Output:</strong> &quot;111&quot;
<strong>Explantion:</strong> (-2)<sup>2</sup> + (-2)<sup>1</sup> + (-2)<sup>0</sup> = 3
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> n = 4
<strong>Output:</strong> &quot;100&quot;
<strong>Explantion:</strong> (-2)<sup>2</sup> = 4
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>0 &lt;= n &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    string baseNeg2(int n) {
        string ans = "";
        if(n == 0) return "0";
        while(n){
            ans = ((n&1) ?  "1" : "0") + ans;
            n = -(n >> 1);
        }
        return ans;
    }
};
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