class Solution {
public:
string convert(string s, int numRows) {
string t;
int len = s.length();
int n;
if (numRows > 2) //这个地方要特殊处理一下，当是只有一行或是两行时候两列中间没有字母
n = numRows * 2 - 2;
else n = numRows;
for (int i = 0; i < numRows; i++) {
if (i == 0 || i == numRows - 1) {
int id = i;
while (id < len) t+=s[id], id += n;
}
else {
int id = i;
while (id < len) {
t+= s[id];
id = id + (numRows - i-1)*2;
if (id < len) t+= s[id];
else break;
id = id + (i) * 2;
}
}
}
return t;
}
};
