<p>The string <code>&quot;PAYPALISHIRING&quot;</code> 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>

<pre>
P   A   H   N
A P L S I I G
Y   I   R
</pre>

<p>And then read line by line: <code>&quot;PAHNAPLSIIGYIR&quot;</code></p>

<p>Write the code that will take a string and make this conversion given a number of rows:</p>

<pre>
string convert(string s, int numRows);
</pre>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;PAYPALISHIRING&quot;, numRows = 3
<strong>Output:</strong> &quot;PAHNAPLSIIGYIR&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;PAYPALISHIRING&quot;, numRows = 4
<strong>Output:</strong> &quot;PINALSIGYAHRPI&quot;
<strong>Explanation:</strong>
P     I    N
A   L S  I G
Y A   H R
P     I
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;A&quot;, numRows = 1
<strong>Output:</strong> &quot;A&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 1000</code></li>
	<li><code>s</code> consists of English letters (lower-case and upper-case), <code>&#39;,&#39;</code> and <code>&#39;.&#39;</code>.</li>
	<li><code>1 &lt;= numRows &lt;= 1000</code></li>
</ul>

class Solution {
public:
    string convert(string s, int numRows) {
        string result;
        if(numRows == 1 || s.size() <= numRows)
            return s;
        unordered_map<int, vector<char>>test;
        int reverse = 1;
        int begin = 0;
        for(int i = 0;i<s.size();i++)
        {
            begin += reverse;
            if(begin == 1)
                reverse = 1;
            else if(begin == numRows)
                reverse = -1;
            test[begin].push_back(s.at(i));
        }
        //for(int i = 0;i<test[2].size();i++)
            //cout << test[2].at(i) <<endl;
        //int k = 0;
        //cout << test[1].at(0) << endl;
        // for(auto &a:test)
        //     for(auto &b : a.second)
        //     {
        //         cout << "j: " << j <<endl;
        //         cout << "char: " << b <<endl;
        //         s.at(j++) = b;
        //     }

        //int k = 0;
        for(int i = 1;i<=numRows;i++)
        {
            for(int j = 0;j<test.at(i).size();j++)
            {
                //s.at((i-1)*numRows+j) = test.at(i).at(j);
                result.push_back(test.at(i).at(j));
            } 
        }

        return result;
    }
};
20843