Excel Sheet Column Number

Package Cn.edu.xidian.sselab;
/**
* Title:excel Sheet Column number
* Content:
* related to question Excel Sheet Column Title
* Given A column title as appear in an Excel sheet, return the its corresponding column number.
* For example:

* A-1
* B-2
* C-3
 *  ...
*-Z
* AA
* AB
 */
public class Titletonumber {

This is a failed case, because the way to solve the problem with the switch cases, the result of a very large amount of code
Actually want to know a corresponds to 1,b corresponding to 2 such result, completely can use the obtained character minus a plus 1 can get the value
public int titletonumbers (String s) {
int len = S.length ();
int result = 0;
int position = 0;
for (int i=0;i<len;i++) {
Char temp = S.charat (i);
Position = position (temp);
Result + = Math.pow (len-i-1) * position;
}
return result;
}
public int position (char temp) {
int position = 0;
Switch (temp) {
Case ' A ': position = 1;break;
Case ' B ': position = 2;break;
Case ' C ': position = 3;break;
Case ' D ': position = 4;break;
Case ' E ': position = 5;break;
Case ' F ': position = 6;break;
Case ' G ': position = 7;break;
Case ' H ': position = 8;break;
Case ' I ': position = 9;break;
Case ' J ': position = 10;break;
Case ' K ': position = 11;break;
Case ' L ': position = 12;break;
Case ' M ': position = 13;break;
Case ' N ': position = 14;break;
Case ' O ': position = 15;break;
Case ' P ': position = 16;break;
Case ' Q ': position = 17;break;
Case ' R ': position = 18;break;
Case ' S ': position = 19;break;
Case ' T ': position = 20;break;
Case ' U ': position = 21;break;
Case ' V ': position = 22;break;
Case ' W ': position = 23;break;
Case ' X ': position = 24;break;
Case ' Y ': position = 25;break;
Case ' Z ': position = 26;break;
}
return position;
}

The correct solution:
This eliminates the hassle of the switch case to solve the corresponding relationship code, very concise
This can actually convert the title into a 26-character conversion process, so be careful not to mistake it.
public int Titletonumber (String s) {
int len = S.length ();
int result = 0;
for (int i=0;i<len;i++) {
Char temp = S.charat (i);
Result + = Math.pow (len-i-1) * (temp-' A ' + 1);
}
return result;
}

}

Excel Sheet Column Number