【leetcode with java】6 ZigZag Conversion

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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   RAnd 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

【思路】

（参考：http://www.cnblogs.com/sanghai/p/3632528.html）

声明含有nRows个字符串的数组，每个数组用来存放ZigZag后的每一行，然后按照原来的顺序沿着ZigZag路线逐个把字符添加到对应的字符串尾部；

最后将nRows个字符串合并为一个，即为要求的结果。

【上码】

/*

 * O(n^2) *  */public class Solution1 {public String convert(String s, int nRows) {if(s == null || s.length() == 0){ return ""; }StringBuffer[] stringBuffer = new StringBuffer[nRows];for(int i=0; i<nRows; i++){ stringBuffer[i] = new StringBuffer(); }int p = 0, len = s.length(), q;while(p < len){for(q=0; q<nRows & p<len; q++){ stringBuffer[q].append(s.charAt(p++)); }for(q-=2; q>0     & p<len; q--){ stringBuffer[q].append(s.charAt(p++)); }}for(int i=1; i<nRows; i++){stringBuffer[0].append(stringBuffer[i]);}return stringBuffer[0].toString();}}

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