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 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
解答
根据mod分情况讨论。
class Solution {
public:
string convert(string s, int numRows) {
int len = s.length();
if (numRows == 1) {
return s;
}
string news = "";
for (int i = 0; i < len; i++) {
if (i % (2 * (numRows - 1)) == 0) {
news.push_back(s[i]);
}
}
for (int j = 1; j <= (numRows - 2); j++) {
for (int i = 0; i < len; i++) {
if (i % (2 * (numRows - 1)) == j || i % (2 * (numRows - 1)) == (2 * (numRows - 1) - j)) {
news.push_back(s[i]);
}
}
}
for (int i = 0; i < len; i++) {
if (i % (2 * (numRows - 1)) != 0 && i % (numRows - 1) == 0) {
news.push_back(s[i]);
}
}
return news;
}
};
题外话
可以一次循环搞定的，懒得改了，击败了9.02%的代码可还行哈哈哈。（待续）
