Question 6 of leetcode -- zigzag Conversion

Problem:

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   NA P L S I I GY   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)Shocould return"Pahnaplsiigyir".

After a string is represented in the font "of", it is combined by each line to output a new string.

I learned the O (n) algorithm in my blog.

Create nrows strings, copy the coordinates of S to each string, and use pushback. The output of the last append connection. The Code is as follows:

class Solution {  public:      string convert(string s, int nRows)      {              if (nRows <= 1 || s.length() < 2)              return s;            string *s_arr = new string[nRows];          int nCount = 2 * (nRows - 1);  // 每个循环的轮回 也就是 2倍的nRows - 2          for (int i = 0; i < s.length(); ++i)          {              s_arr[nRows - 1 -abs(nRows - 1 - (i%nCount))].push_back(s[i]);          }            string str_result;          for (int i = 0; i < nRows; ++i)              str_result.append(s_arr[i]);            return str_result;      }  };

Coordinate matching is the key, and the logic thinking of mathematics is indeed strong. You can give an example of four rows.

Question 6 of leetcode -- zigzag Conversion