Leetcode 168 Excel Sheet Column Title

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 

Credits:
Special thanks to @ifanchu for adding this problem and creating all test cases.

解题思路:

完全可以用ascii码来做啊, 但是面试的时候很可能记不住26个字母在ascii码表中的顺序, 所以第二遍的code就是用的string数组来做的~

注意Z时候的情况就可以啦~

public String convertToTitle(int n) {
        String str = "";
        String[] ch = {"Z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y"};
        while(n != 0){
            int temp = n % 26;
            if(temp == 0){
                str = ch[temp] + str;
                n--;
            }else 
                str = ch[temp] + str;
            n /= 26;
        }
        return str;
    }