LeetCode-Excel Sheet Column Number
阿新 • • 發佈:2018-12-12
Description: 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
題意:給定Excel工作表中顯示的列標題,返回其對應的列號;
解法:列標題應當是用字母表示的27進位制,每當超過27時便進一(A-1; B-2; C-3…Z-26);例如對於AZ來說,對其再加一為BA;
Java
class Solution { public int titleToNumber(String s) { int columnNumber = 0; int order = 1; for (int i = s.length() - 1; i >= 0; i--) { columnNumber += (s.charAt(i) - 'A' + 1) * order; order *= 26; } return columnNumber; } }