class Solution{
    public : 
        int binaryGap(int n){
            int last = -1;
            int ans =0;
            for(int i =0;i<32;i++){
                if(n>>i & 1){
                    if(last!=-1)
                        ans = max(ans, i-last);
                    last = i;
                }
            }
            return ans;
        }
};
//We'll store last, the index of the last set bit encountered. If n has the ith bit set, answer is i - last, and then the new last value would be last = i.
//TC : o(logn) , logn is the number of digits in the binary representation of n 
//SC : o(1)