complete 221 by python

Author: bbruceyuan

README.md

@@ -1,9 +1,9 @@
 # Keep thinking, keep alive
-Until 2018-04-20 19:57:32, I have solved **97** / **734** problems while **133** are still locked.
+Until 2018-05-06 21:55:10, I have solved **98** / **746** problems while **133** are still locked.
 
 Completion statistic: 
 1. JavaScript: 59 
-2. Python: 47
+2. Python: 48
 3. C++: 1
 4. Java: 1
 
@@ -217,7 +217,7 @@ Note: :lock: means you need to buy a book from LeetCode
 |218|[The Skyline Problem](https://leetcode.com/problems/the-skyline-problem/description/) |Hard|To Do|To Do|To Do|To Do|
 |219|[Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii/description/) |Easy|[JavaScript](https://github.com/hey-bruce/algorithms_and_oj/blob/master/leetcode-algorithms/219.%20Contains%20Duplicate%20II/containsNearbyDumplicate.js)|To Do|To Do|To Do|
 |220|[Contains Duplicate III](https://leetcode.com/problems/contains-duplicate-iii/description/) |Medium|[JavaScript](https://github.com/hey-bruce/algorithms_and_oj/blob/master/leetcode-algorithms/220.%20Contains%20Duplicate%20III/containsNearbyAlmostDuplicate.js)|To Do|To Do|To Do|
-|221|[Maximal Square](https://leetcode.com/problems/maximal-square/description/) |Medium|To Do|To Do|To Do|To Do|
+|221|[Maximal Square](https://leetcode.com/problems/maximal-square/description/) |Medium|To Do|[Python](https://github.com/hey-bruce/algorithms_and_oj/blob/master/leetcode-algorithms/221.%20Maximal%20Square/solution.py)|To Do|To Do|
 |222|[Count Complete Tree Nodes](https://leetcode.com/problems/count-complete-tree-nodes/description/) |Medium|To Do|To Do|To Do|To Do|
 |223|[Rectangle Area](https://leetcode.com/problems/rectangle-area/description/) |Medium|To Do|To Do|To Do|To Do|
 |224|[Basic Calculator](https://leetcode.com/problems/basic-calculator/description/) |Hard|To Do|To Do|To Do|To Do|
@@ -747,3 +747,15 @@ Note: :lock: means you need to buy a book from LeetCode
 |817|[Linked List Components](https://leetcode.com/problems/linked-list-components/description/) |Medium|To Do|To Do|To Do|To Do|
 |818|[Race Car](https://leetcode.com/problems/race-car/description/) |Hard|To Do|To Do|To Do|To Do|
 |819|[Most Common Word](https://leetcode.com/problems/most-common-word/description/) |Easy|To Do|To Do|To Do|To Do|
+|820|[Short Encoding of Words](https://leetcode.com/problems/short-encoding-of-words/description/) |Medium|To Do|To Do|To Do|To Do|
+|821|[Shortest Distance to a Character](https://leetcode.com/problems/shortest-distance-to-a-character/description/) |Easy|To Do|To Do|To Do|To Do|
+|822|[Card Flipping Game](https://leetcode.com/problems/card-flipping-game/description/) |Medium|To Do|To Do|To Do|To Do|
+|823|[Binary Trees With Factors](https://leetcode.com/problems/binary-trees-with-factors/description/) |Medium|To Do|To Do|To Do|To Do|
+|824|[Goat Latin](https://leetcode.com/problems/goat-latin/description/) |Easy|To Do|To Do|To Do|To Do|
+|825|[Friends Of Appropriate Ages](https://leetcode.com/problems/friends-of-appropriate-ages/description/) |Medium|To Do|To Do|To Do|To Do|
+|826|[Most Profit Assigning Work](https://leetcode.com/problems/most-profit-assigning-work/description/) |Medium|To Do|To Do|To Do|To Do|
+|827|[Making A Large Island](https://leetcode.com/problems/making-a-large-island/description/) |Hard|To Do|To Do|To Do|To Do|
+|828|[Unique Letter String](https://leetcode.com/problems/unique-letter-string/description/) |Hard|To Do|To Do|To Do|To Do|
+|829|[Consecutive Numbers Sum](https://leetcode.com/problems/consecutive-numbers-sum/description/) |Medium|To Do|To Do|To Do|To Do|
+|830|[Positions of Large Groups](https://leetcode.com/problems/positions-of-large-groups/description/) |Easy|To Do|To Do|To Do|To Do|
+|831|[Masking Personal Information](https://leetcode.com/problems/masking-personal-information/description/) |Medium|To Do|To Do|To Do|To Do|

leetcode-algorithms/221. Maximal Square/solution.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+# created by BBruceyuan on 18-5-2
+
+
+import numpy as np
+
+
+class Solution:
+    def maximalSquare(self, matrix):
+        """
+        :type matrix: List[List[str]]
+        :rtype: int
+        """
+        if len(matrix) == 0:
+            return 0
+        matrix = np.array(matrix)
+        row, column = len(matrix), len(matrix[0])
+        dp = np.zeros((row + 1, column + 1))
+        print(dp)
+        max_sqlen = 0
+        for i in range(1, row + 1):
+            for j in range(1, column + 1):
+                if matrix[i - 1][j - 1] == '1':
+                    dp[i][j] = min(dp[i][j - 1], dp[i - 1][j], dp[i - 1][j - 1]) + 1
+                    max_sqlen = max(max_sqlen, dp[i][j])
+        return int(max_sqlen ** 2)
+
+
+def main():
+    s = Solution()
+    a = s.maximalSquare([["1","0","1","0","0"],
+                         ["1","0","1","1","1"],
+                         ["1","1","1","1","1"],
+                         ["1","0","0","1","0"]])
+    print(a)
+
+
+if __name__ == '__main__':
+    main()