6 ZigZag Conversion

The string “PAYPALISHIRING” is written in a zigzag（Z字形） 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".

Tags:String

import java.util.*;

public class No6 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        String s = scanner.next();
        int n = scanner.nextInt();

        String str = convert(s, n);

        System.out.println(str);
    }

    public static String convert(String s, int n) {

        if(n==1)
            return s;

        int dot = n + n - 2; // 折点

        String[] str = new String[n];
        String str1 = "";

        for (int a = 0; a < n; a++) {
            str[a] = "";
        }

        int i = 0;
        while (dot * i < s.length()) {
            str[0] += s.charAt(dot * i);
            i++;
        }
        // return str[0];

        int dots;


        for (int j = 1; j < n - 1; j++) { // j表示行数；从第2行到倒数第2行；

            i = 0;  //重置为0；
            while ((dots = dot * i) < s.length()) {

                if ((dots + j) < s.length()) {
                    str[j] += "" + s.charAt(dots + j);
                }
                if ((dots + dot - j) < s.length()) {
                    str[j] += "" + s.charAt(dots + dot - j);
                }
                i++;
            }
        }

        i = 0; // 重置i；
        while ((n - 1 + dot * i) < s.length()) {
            str[n - 1] += s.charAt(n - 1 + dot * i);
            i++;
        }

        for (i = 0; i < n; i++) {
            str1 += str[i];
        }

        return str1;

    }

}

input

abcdefghijklmnopqrstuvwxyz 5

output

aiqybhjprxzcgkoswdflntvemu

0	1	2	3	4	5	6	7	8	9	10	11	12
a0				i8				q16				y24
b1			h7	j9			p15	r17			x23	z25
c2		g6		k10		o14		s18		w22
d3	f5			l11	n13			t19	v21
e4				m12				u20