ZigZag Conversion

最新推荐文章于 2025-09-10 21:59:39 发布

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最新推荐文章于 2025-09-10 21:59:39 发布

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文章标签： runtime

原文链接：http://www.cnblogs.com/amazingzoe/p/4870605.html

本文介绍了一种将字符串以Z形方式排列并按行读取的算法实现。该算法通过特定的步骤处理输入字符串，并根据指定的行数返回转换后的结果。例如，将PAYPALISHIRING以3行Z形方式排列后，输出为PAHNAPLSIIGYIR。

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".

Runtime: 16ms

 1 class Solution {
 2 public:
 3     string convert(string s, int numRows) {
 4         if(numRows <= 1) return s;
 5         if(s.empty()) return s;
 6         
 7         string result;
 8         int size = 2 * numRows - 2;
 9         for(int i = 0; i < numRows; i++){
10             for(int j = i; j < s.length(); j += size){
11                 result += s[j];
12                 if(i != 0 && i != numRows - 1){
13                     int temp = j + size - 2 * i;
14                     if(temp < s.length())
15                         result += s[temp];
16                 }
17             }
18         }
19         return result;
20     }
21 };