<p>Given a positive integer <code>n</code>, return the number of the integers in the range <code>[0, n]</code> whose binary representations <strong>do not</strong> contain consecutive ones.</p>

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

<pre>
<strong>Input:</strong> n = 5
<strong>Output:</strong> 5
<strong>Explanation:</strong>
Here are the non-negative integers &lt;= 5 with their corresponding binary representations:
0 : 0
1 : 1
2 : 10
3 : 11
4 : 100
5 : 101
Among them, only integer 3 disobeys the rule (two consecutive ones) and the other 5 satisfy the rule. 
</pre>

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

<pre>
<strong>Input:</strong> n = 1
<strong>Output:</strong> 2
</pre>

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

<pre>
<strong>Input:</strong> n = 2
<strong>Output:</strong> 3
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    int f(int i,bool flag,int &n){
        // cout<<i<<" "<<flag<<endl;
        int ans=0;
        if(i<=-1)return 1;
        if(flag){
            if(n&(1<<i)){
                ans+=f(i-1,false,n);
                if(i==0 || n&(1<<(i-1))){
                    ans+=f(i-2,false,n);
                }else{
                    ans+=f(i-2,true,n);
                }
            }else{
                ans+=f(i-1,true,n);
            }
        }else{
            ans+=f(i-1,false,n);
            ans+=f(i-2,false,n);
        }
        return ans;
    }
    int findIntegers(int n) {
        int i=30;
        while(!(n&(1<<i))){
            i--;
        }
        return f(i,true,n);
    }
};
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