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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 s, int numRows);
Example 1:
Input: s = "PAYPALISHIRING", numRows = 3 Output: "PAHNAPLSIIGYIR"
Example 2:
Input: s = "PAYPALISHIRING", numRows = 4 Output: "PINALSIGYAHRPI" Explanation: P I N A L S I G Y A H R P I
Example 3:
Input: s = "A", numRows = 1 Output: "A"
Constraints:
1 <= s.length <= 1000
s
consists of English letters (lower-case and upper-case),','
and'.'
.1 <= numRows <= 1000
Code in C++
class Solution {
public:
string convert(string s, int numRows) {
if (numRows == 1) return s;
string result;
int n = s.size();
int cycle = 2 * numRows - 2;
for (int i = 0; i < numRows; i++) {
for (int j = 0; j + i < n; j += cycle) {
result += s[j + i];
if (i != 0 && i != numRows - 1 && j + cycle - i < n)
result += s[j + cycle - i];
}
}
return result;
}
};