LeetCode(6) ZigZag Conversion解题报告

z型转换

问题:

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”.

解题方案:

这道题目比较简单，就不做分析了，直接贴代码。

public String convert(String s, int numRows) {
StringBuffer[] sbs = new StringBuffer[numRows];
for (int i = 0; i < sbs.length; i++) {
sbs[i] = new StringBuffer();
}
int flag = 0;
int step = -1;
for (int i = 0; i < s.length(); i++) {
sbs[flag].append(s.charAt(i));
if (flag == numRows - 1 || flag == 0) {
step = -step;
}
flag += step;
if (flag < 0) {
flag = 0;
}
if (flag > numRows - 1) {
flag = numRows - 1;
}
}

StringBuffer result = new StringBuffer();
for(StringBuffer sb : sbs) {
result.append(sb);
}
return result.toString();
}