[LeetCode] 006.ZigZag Conversion (Java)

Problem description

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".

Code

class Solution {
    public String convert(String s, int numRows) {
        
        String[] res = new String[numRows];
        for(int i = 0; i < numRows; i++) {
            res[i] = "";
        }
        int len = s.length();
        
        if(len == 0) {
            return "";
        } 
        
        int l = 0;
        int point = 0;
        
        while(l < len) {
            if(numRows >= 3) {
                if(point == 0) {
                    for(int i = 0; i < numRows; i++) {
                        if(l == len) {
                            break;
                        }
                        res[point++] += s.charAt(l++);
                    }
                    point -= 2;
                } else {
                    res[point--] += s.charAt(l++);
                }  
            } else {
                for(int i = 0; i < numRows; i++) {
                    if(l == len) {
                        break;
                    }
                    res[i] += s.charAt(l++);
                }
            }
                                
        }
        String ss = "";
        for(int i = 0; i < numRows; i++) {
            ss += res[i];
        }
        return ss;
    }
}

Analysis

• String数组主要初始化。