LeetCode OJ(6.ZigZag Conversion)

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 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”.

题目练习的意义不大，主要是找到数学规律。

class Solution {
public:
string convert(string s, int nRows) {
string result;
if (nRows <=1) return s;
for (int i = 0; i < nRows; ++i) {
for (int j = i; j < s.length(); j += 2 * (nRows - 1)) {
result.push_back(s[j]);
if (i > 0 && i < nRows - 1) {
if (j + 2 * (nRows - i - 1) < s.length())
result.push_back(s[j + 2 * (nRows - i - 1)]);
}
}
}
return result;
}
};