Create longest-common-subsequence.py

Author: kamyu104

Python/longest-common-subsequence.py

@@ -0,0 +1,19 @@
+# Time:  O(m * n)
+# Space: O(min(m, n))
+
+class Solution(object):
+    def longestCommonSubsequence(self, text1, text2):
+        """
+        :type text1: str
+        :type text2: str
+        :rtype: int
+        """
+        if len(text1) < len(text2):
+            return self.longestCommonSubsequence(text2, text1)
+
+        dp = [[0 for _ in xrange(len(text2)+1)] for _ in xrange(2)]
+        for i in xrange(1, len(text1)+1):
+            for j in xrange(1, len(text2)+1):
+                dp[i%2][j] = dp[(i-1)%2][j-1]+1 if text1[i-1] == text2[j-1] \
+                             else max(dp[(i-1)%2][j], dp[i%2][j-1])
+        return dp[len(text1)%2][len(text2)]