168.md

#168. Excel Sheet Column Title 题目链接

由于A对应1，Z对应26，所以每次n先减一，然后插入到字符串最前面

public class Solution {
    public String convertToTitle(int n) {
        StringBuilder sb = new StringBuilder();
        while (n > 0) {
            n--;
            sb.insert(0, (char)(n % 26 + 'A'));
            n /= 26;
        }
        return sb.toString();
    }
}