Update longest_common_subsequence.py

Author: manthan0227

Dynamic Programming/Longest Common Subsequence/longest_common_subsequence.py

@@ -5,15 +5,15 @@
 
 
 def lcs(n, m, s1, s2):
-    if n == 0 or m == 0:
+    if n == 0 or m == 0: # if the one of the string size 0 then we returned 0
         return 0
-    if s1[n - 1] == s2[m - 1]:
+    if s1[n - 1] == s2[m - 1]: # if string have the same letter then we add one and go to the next letter
         return 1 + lcs(n - 1, m - 1, s1, s2);
-    else:
+    else:                       # otherwise we do maximum of both strings 
         return max(lcs(n, m - 1, s1, s2), lcs(n - 1, m, s1, s2))
 
 if __name__ == "__main__":
     print("Longest Common Subsequence Problem")
-    s1 = input("First String: ")
-    s2 = input("Second String: ")
-    print("Length of the Longest Common Subsequence: ", lcs(len(s1), len(s2), s1, s2))
+    s1 = input("First String: ") # input the first string
+    s2 = input("Second String: ") # input the second string
+    print("Length of the Longest Common Subsequence: ", lcs(len(s1), len(s2), s1, s2)) # len(s) is length of the string s