Create decode-the-slanted-ciphertext.py

Author: kamyu104

Python/decode-the-slanted-ciphertext.py

@@ -0,0 +1,50 @@
+# Time:  O(n)
+# Space: O(1)
+
+class Solution(object):
+    def decodeCiphertext(self, encodedText, rows):
+        """
+        :type encodedText: str
+        :type rows: int
+        :rtype: str
+        """
+        cols = len(encodedText)//rows
+        k = len(encodedText)
+        for i in reversed(xrange(cols)):
+            for j in reversed(xrange(i, len(encodedText), cols+1)):
+                if encodedText[j] != ' ':
+                    k = j
+                    break
+            else:
+                continue
+            break
+        result = []
+        for i in xrange(cols):
+            for j in xrange(i, len(encodedText), cols+1):
+                result.append(encodedText[j])
+                if j == k:
+                    break
+            else:
+                continue
+            break
+        return "".join(result)
+
+
+# Time:  O(n)
+# Space: O(n)
+class Solution2(object):
+    def decodeCiphertext(self, encodedText, rows):
+        """
+        :type encodedText: str
+        :type rows: int
+        :rtype: str
+        """
+        cols = len(encodedText)//rows
+        result = []
+        for i in xrange(cols):
+            for j in xrange(i, len(encodedText), cols+1):
+                result.append(encodedText[j])
+        while result and result[-1] == ' ':
+            result.pop()
+        return "".join(result)
+