Question
Formatted question description: https://leetcode.ca/all/171.html
171 Excel Sheet Column Number
Given a column title as appear in an Excel sheet, return its corresponding column number.
For example:
A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28
...
Example 1:
Input: "A"
Output: 1
Example 2:
Input: "AB"
Output: 28
Example 3:
Input: "ZY"
Output: 701 (26*26+25)
Algorithm
It is equivalent to a problem of converting from hexadecimal to decimal. It is not difficult, as long as the conversion is bit by bit.
Code
Java
public class Excel_Sheet_Column_Number {
class Solution {
public int titleToNumber(String s) {
int result = 0;
for (int i = 0; i < s.length(); i++) {
result = result * 26 + (s.charAt(i) - 'A' + 1);
}
return result;
}
}
}