6. Z 字形变换

 1 //找规律题 等差数列 2m-2
 2 class Solution 
 3 {
 4 public:
 5     string convert(string s, int m) 
 6     {
 7         if(m == 1) return s;
 8         int n = s.size();
 9         string res;
10         for(int i = 0;i < m;i ++)
11         {
12             if(i == 0 || i == m-1)
13             {
14                 for(int k = 0;k <= n/m;k ++)
15                 {
16                     int temp = i + k*(2*m-2);
17                     if(temp >= n) break;
18                     res.push_back(s[temp]);
19                 }
20             }
21             else
22             {
23                 int a1 = i;
24                 int b1 = 2*m-2-i;
25                 for(int k = 0;k <= n/m;k ++)
26                 {
27                     int temp1 = a1 + k*(2*m-2);
28                     if(temp1 >= n) break;
29                     res.push_back(s[temp1]);
30 
31                     int temp2 = b1 + k*(2*m-2);
32                     if(temp2 >= n) break;
33                     res.push_back(s[temp2]);
34                 }
35             }
36         }
37         return res;
38     }
39 };