[Leetcode] 6.Z shaped transform C ++ (to find the law method)

/*
将一个给定字符串根据给定的行数，以从上往下、从左到右进行 Z 字形排列。
*/

#include "iostream"
#include "string"
#include "vector"

using namespace std;

class Solution
{
public:
    string convert(string s, int numRows)
    {
        if (numRows == 1)
            return s;

        int len = s.length();
        int step = 2 * numRows - 2; // 间距

        int curor, sub;
        string ans;

        for (int i = 0; i < numRows; i++)
        {
            curor = i;
            sub = 2 * i;
            while (curor < len)
            {
                ans += s[curor];
                sub = step - sub;
                curor += (i == 0 || i == numRows-1) ? step : sub;
            }
        }
        return ans;
    }
};

int main()
{
    string s;
    int numRows;

    cin >> s;
    cin >> numRows;

    Solution so;
    string ans = so.convert(s, numRows);

    cout << ans << " " << ans.size() << endl;
    return 0;
}