Leetcode-967 Numbers With Same Consecutive Differences(连续差相同的数字)

#define _for(i,a,b) for(int i = (a);i < (b);i ++)
class Solution
{
    public:
        vector<int> rnt;
        void dfs(int N,int K,int h,string s)
        {
            if(h==N)
            {
                stringstream ss;
                ss<<s;
                int tmp;
                ss>>tmp;
                rnt.push_back(tmp);
                return ;
            }
            if(h==0)
            {
                _for(i,0,10)
                {
                    s+=i+'0';
                    dfs(N,K,h+1,s);
                    s.pop_back();
                }
            }
            else
            {
                _for(i,0,10)
                {
                    if(s[h-1]=='0'&&h==1)
                        break;
                    if(abs(i+'0'-s[h-1])==K)
                    {
                        s+=i+'0';
                        dfs(N,K,h+1,s);
                        s.pop_back();
                    }
                }
            }
        }
        vector<int> numsSameConsecDiff(int N, int K)
        {
            rnt.clear();
            string s;
            dfs(N,K,0,s);
            return rnt;
        }
};