6. ZigZag Conversion

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". 

解析

// 6. ZigZag Conversion
class Solution_6 {
public:
	string convert(string s, int numRows) {
		if (numRows<=1)
		{
			return s;
		}
		//vector<string> vec; //numRows行 //
		//string vec[numRows]; bug

		string* vec = new string[numRows];
		int step = 0, row = 0;
		for (int i = 0; i < s.size();++i)
		{
			vec[row].push_back(s[i]);
			if (row == 0)
			{
				step = 1;
			}
			if (row == numRows-1)
			{
				step = -1;
			}
			row = row + step;
		}

		string str="";
		for (int i = 0; i < numRows; i++)
		{
			str += vec[i];
		}
		delete[] vec;

		return str;
	}
};

题目来源

• 6. ZigZag Conversion