LeetCode 168. Excel Sheet Column Title

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

     -> A
     -> B
     -> C
    ...
     -> Z
     -> AA
     -> AB 

分析：

类比10进制数，此问题可简化为26进制数的问题（0-25）。

char* convertToTitle(int n) {
    int tmp = n;
    ;
    char *str = NULL;

    ) {
        i++;
        tmp = (tmp-)/;
    }

    str = (char *) malloc(i*sizeof(char));
    tmp = n;

    ; i--) {
        str[i-] = (tmp-)%+'A';
        tmp =(tmp-)/;
    }

    return str;
}