原题链接:https://leetcode.com/problems/zigzag-conversion/
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 RAnd 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"
.
char* convert(char* s, int numRows) {
if(numRows == 1)
return s;
int len = strlen(s);
char* ret = (char *)malloc((len + 1) * sizeof(char));
int i, j, index = 0;
for(i = 0; i < numRows; ++i) {
j = i;
while(j < len) {
ret[index++] = s[j];
if(i == 0 || i == numRows - 1)
j += 2 * numRows - 2;
else {
j += 2 * (numRows - i - 1);
if(j < len) {
ret[index++] = s[j];
j += 2 * i;
}
}
}
}
for(i = 0; i < len; ++i)
s[i] = ret[i];
free(ret);
return s;
}