题目

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   NA P L S I I GY   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"

.

方法

将字符串Z字形排列，然后输出新的字符串。

仅仅须要循环处理就可以。递增在递减。

public String convert(String s, int nRows) {	        String[] subString = new String[nRows];	        	        for(int i =0; i < nRows; i ++){	            subString[i] = "";	        }	        	        int flag = 0;	        int currentRows = 0;	        String convertString ="";	        if(nRows == 1){	            return s;	        }	        for(int i = 0; i < s.length(); i ++){	            if(flag == 0){	                if(currentRows < nRows){	                    subString[currentRows] +=s.charAt(i);	                    currentRows ++;	                }	                if(currentRows == nRows){	                    flag = 1;	                    currentRows -- ;	                }	                	            }else{	                if(currentRows > 0){	                    subString[currentRows - 1] +=s.charAt(i);	                    currentRows --;	                }	                if(currentRows == 0){	                    flag = 0;	                    currentRows ++;	                }	            }	        }	        	        	        	        for(int i = 0; i < nRows; i ++){	            convertString += subString[i];	        }	        return convertString;	    }