leetcode 171

python

Author: kyle8998

README.md

@@ -96,6 +96,7 @@ Personal Practice Set - Doing One a Day (sometimes) in a Variety of Languages (M
 | 148| Medium     | [Sort List](leetcode/148-Medium-Sort-List/problem.md)                                        | [Python](leetcode/148-Medium-Sort-List/answer.py)                 |
 | 155| Easy       | [Min Stack](leetcode/155-Easy-Min-Stack/problem.md)                                          | [Python](leetcode/155-Easy-Min-Stack/answer.py)                   |
 | 168| Easy       | [Excel Sheet Column Title](leetcode/168-Easy-Excel-Sheet-Column-Title/problem.md)            | [Python](leetcode/168-Easy-Excel-Sheet-Column-Title/answer.py)    |
+| 171| Easy       | [Excel Sheet Column Number](leetcode/171-Easy-Excel-Sheet-Column-Number/problem.md)          | [Python](leetcode/171-Easy-Excel-Sheet-Column-Number/answer.py)   |
 | 173| Medium     | [Binary Search Tree Iterator](leetcode/173-Medium-Binary-Search-Tree-Iterator/problem.md)    | [Python](leetcode/173-Medium-Binary-Search-Tree-Iterator/answer.py) |
 | 188| Hard       | [Best Time to Buy and Sell Stock IV](leetcode/188-Hard-Best-Time-To-Buy-And-Sell-Stock-IV/problem.md) | [Python](leetcode/188-Hard-Best-Time-To-Buy-And-Sell-Stock-IV/answer.py) |
 | 200| Medium     | [Number of Islands](leetcode/200-Medium-Number-Of-Islands/problem.md)                        | [Python](leetcode/200-Medium-Number-Of-Islands/answer.py)         |

leetcode/171-Easy-Excel-Sheet-Column-Number/answer.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+
+#-------------------------------------------------------------------------------
+class Solution:
+    def titleToNumber(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        i, result = 0, 0
+        for letter in s[::-1]:
+            digit = (ord(letter)-ord('A'))+1
+            for _ in range(i):
+                digit *= 26
+            i += 1
+            result += digit
+        return result
+        
+#-------------------------------------------------------------------------------

leetcode/171-Easy-Excel-Sheet-Column-Number/problem.md

@@ -0,0 +1,23 @@
+# Problem 171: Excel Sheet Column Number
+
+#### Difficulty: Easy
+
+#### Problem
+
+Given a column title as appear in an Excel sheet, return its corresponding column number.
+
+#### Example
+
+<pre>
+Example 1:
+Input: "A"
+Output: 1
+
+Example 2:
+Input: "AB"
+Output: 28
+
+Example 3:
+Input: "ZY"
+Output: 701
+</pre>