Given a positive integer, return its corresponding column title as appear in an Excel sheet.
For example:
1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
一刷
题解：只能从后往前append,因为每次需要n--然后与26求余数。
public class Solution {
public String convertToTitle(int n) {
StringBuilder sb = new StringBuilder();
while(n>0){
n--;
sb.insert(0, (char)('A' + n%26));
n /= 26;
}
return sb.toString();
}
}
