Add solution for problem 1143. (Tahanima#84)

Author: jabertuhin

Algorithms/Medium/1143_LongestCommonSubsequence/Solution.py

@@ -0,0 +1,20 @@
+class Solution:
+    def longestCommonSubsequence(self, text1: str, text2: str) -> int:
+        text1_length = len(text1)
+        text2_length = len(text2)
+
+        lcs_array = self._get_initialized_lcs_array(text1_length, text2_length)
+                
+        for idx_2, text2_char in enumerate(text2):
+            row = idx_2 + 1
+            for idx_1, text1_char in enumerate(text1):
+                col = idx_1 + 1
+                if text1_char == text2_char:
+                    lcs_array[row][col] = lcs_array[row-1][col-1] + 1
+                else:
+                    lcs_array[row][col] = max(lcs_array[row][col-1], lcs_array[row-1][col])
+
+        return lcs_array[row][col]
+
+    def _get_initialized_lcs_array(self, text1_length, text2_length):
+        return [[0]*(text1_length+1) for _ in range(text2_length + 1)]