Excel Sheet Column Number

Change-Id: Ib63bab271f501a61843472d94861dfceff692598

Author: applewjg

ExcelSheetColumnNumber.java

@@ -0,0 +1,34 @@
+/*
+ Author:     King, [email protected]
+ Date:       Jul 11, 2013
+ Problem:    Unique Binary Search Trees II
+ Difficulty: Medium
+ Source:     https://oj.leetcode.com/problems/excel-sheet-column-number/
+ Notes:
+ Related to question Excel Sheet Column Title
+
+ 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 
+
+ Solution: 1. ...
+*/
+
+public class Solution {
+    public int titleToNumber(String s) {
+        int res = 0;
+        if (s.length() == 0) return 0;
+        for (int i = 0; i < s.length(); ++i) {
+            res = res * 26 + s.charAt(i) - 'A' + 1;
+        }
+        return res;
+    }
+}