leetcode problem 6 ZigZag Conversion

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P   A   H   N

A P L S I I G

Y   I   R

And then read line by line: "PAHNAPLSIIGYIR"

Write the code that will take a string and make this conversion given a number of rows:

string convert(string text, int nRows);

convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".

 

 

简单的模拟题。

直接上代码：（Runtime: 26 ms）

class Solution {

public:

    string convert(string s, int nRows) {

        if (nRows == 1)

            return s;

        string res = s;

        int round = 2*nRows - 2;

        int len = res.length();

        int pos = 0;

        for (int i = 0; i < nRows; ++i) {

            int k = 0;

            int cur = k*round+i;



            while (true) {

                cur = k*round + i;

                if (cur >= len)

                    break;

                res[pos++] = s[cur];



                if (i != 0 && i != nRows - 1) {

                    cur = (k+1)*round - i;

                    if (cur >= len)

                        break;

                    res[pos++] = s[cur];

                }

                ++k;

            }

        }

        return res;

    }

};