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".
public class Solution {
public String convert(String s, int numRows) {
if (s == null || s.length() == 0 || numRows <= 0) {
return "";
}
if (numRows == 1) {
return s;
}
StringBuilder sb = new StringBuilder();
int size = 2 * numRows - 2;
for (int i = 0; i < numRows; i++) {
for (int j = i; j < s.length(); j += size) {
sb.append(s.charAt(j));
if (i != 0 && i != numRows - 1) {
int temp = j + size - 2 * i;
if (temp < s.length()) {
sb.append(s.charAt(temp));
}
}
}
}
return sb.toString();
}
}
Hope this helps,
Michael