题干
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
题解1 brute force
class Solution {
public:
string convert(string s, int numRows) {
if(numRows == 1) return s;
vector<string> rows(min(int(s.size()), numRows));
int curRow = 0;
bool goDown = false;
for(char c:s)
{
rows[curRow] += c;
if(curRow == 0 || curRow == numRows - 1) goDown = !goDown;
curRow += goDown ? 1 : -1;
}
string res;
for(string row:rows)
res += row;
return res;
}
};
