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".

 

代码：z字形遍历二维数组。

class Solution {
public:
    string convert(string s, int nRows) 
    {
         if(s.empty()||nRows==1) return s;
         string res; 
         char a[1000][1000];
         memset(a,0,sizeof(a));
         int i=0,j=0,q=0;
         int j_time=0;
         int len=s.size();
         while (i<nRows&&q<len){
             a[i][j]=s[q];
             ++i;++q;
             if(i==nRows&&q<len){
                 --i;
                 j_time=0;
                 while (j_time<(nRows-1)&&q<len){
                     --i;
                     ++j_time;
                     ++j;
                     a[i][j]=s[q];++q;
                 }
                 ++i;
             }
         }
         for (int i=0;i<nRows;++i)
         {
             for (int j=0;j<len;++j)
             {
                 if(a[i][j]!='\0')
                     res.push_back(a[i][j]);
             }
         }
         return res;
    }
};