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

 1 /*************************************************************************
 2     > File Name: LeetCode168.c
 3     > Author: Juntaran
 4     > Mail: JuntaranMail@gmail.com
 5     > Created Time: Tue 10 May 2016 08:06:44 PM CST
 6  ************************************************************************/
 7 
 8 /*************************************************************************
 9     
10     Excel Sheet Column Title
11     
12     Given a positive integer, 
13     return its corresponding column title as appear in an Excel sheet.
14 
15     For example:
16 
17         1 -> A
18         2 -> B
19         3 -> C
20         ...
21         26 -> Z
22         27 -> AA
23         28 -> AB 
24         
25  ************************************************************************/
26  
27 #include <stdio.h>
28 
29 char* convertToTitle( int n )
30 {
31     if( n < 1 )
32     {
33         return "";
34     }
35     int i;
36     int count = 0;
37     for( i=n-1; i>=0; i=i/26-1 )
38     {
39         count ++;
40     }
41     char* ret = (char*)malloc(sizeof(char)*count);
42     for( i=n-1; i>=0; i=i/26-1 )
43     {
44         ret[--count] = i%26 + 'A';
45     }
46     return ret;
47 }
48 
49 int main()
50 {
51     int n = 28;
52     char* ret = convertToTitle(n);
53     printf("%s
", ret);
54 }