LeetCode: ZigZag Conversion

没考虑到nRows == 1的情况，少数次过

class Solution {
public:
    string convert(string s, int nRows) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function    
        string ret;
        vector<string> t(nRows);
        if (nRows == 1) return s;
        int div = 2 * nRows - 2;
        for (int i = 0; i < s.size(); i++) {
            int pos = i % div;
            if (pos <= nRows-1) t[pos] += s[i];
            else t[div-pos] += s[i];
        }
        for (int i = 0; i < nRows; i++) ret += t[i];
        return ret;
    }
};

 C#

public class Solution {
    public string Convert(string s, int numRows) {
        string ans = "";
        string[] t = new string[numRows];
        if (numRows == 1) return s;
        int div = 2 * numRows - 2;
        for (int i = 0; i < s.Length; i++) {
            int pos = i % div;
            if (pos <= numRows-1) t[pos] += s[i];
            else t[div-pos] += s[i];
        }
        for (int i = 0; i < numRows; i++) ans += t[i];
        return ans;
    }
}