Leetcode-1012 Complement of Base 10 Integer(十进制整数的补码)

#define _for(i,a,b) for(int i = (a);i < (b);i ++)
class Solution
{
    public:
        int bitwiseComplement(int N)
        {
            if(N==0)
                return 1;
            string s;
            while(N)
            {
                s+= N%2+'0';
                N/=2;
            }
            reverse(s.begin(),s.end());
        
            _for(i,0,s.size())
            {
                if(s[i]=='0')
                {
                    s[i] = '1';
                }
                else
                    s[i] = '0';
            }
            
            int rnt = 0;
            for(int i = 0 ;i < s.size();i ++)
            {
                rnt += (s[i]-'0')*pow(2,s.size()-i-1);
              //  cout << rnt << endl;
            }
            return rnt;
        }
};