696. Count Binary Substrings

1. 首先找到0,1交界的地方，存起来；
2. 然后在交界地方比较，左边和左边相等，右边和右边相等；

    int countBinarySubstrings(string s) {
        int n = s.length();
        deque<int> d;
        int sum=0;
        for(int i=1;i<n;i++){
            if(s[i-1] != s[i])
                d.push_back(i);
            
        }
        while(!d.empty()){
            int cur = d.front();
            d.pop_front();
            int left = cur-1;
            sum++;
          //  cout<<"cur:"<<cur<<" sum: "<<sum<<endl;
            while(left>0 && cur<n-1){ 
                if(s[left] == s[left-1]  && s[cur] == s[cur+1])
                    sum++;
                else
                    break;

                cur++;
                left--;
               // cout<<"cur:"<<cur<<" sum:"<<sum<<endl;

            }
            //cout<<"=========="<<endl;
        }
      
        return sum;     
        
    }