Merge pull request #3 from emcc2302/emcc2302-patch-2

Create  Code Testcase Test Result Test Result 5. Longest Palindromic …

Author: emcc2302

Code Testcase Test Result Test Result 5. Longest Palindromic Substring.py

@@ -0,0 +1,22 @@
+def longestPalindrome(self, s):
+        longest_palindrom = ''
+        dp = [[0]*len(s) for _ in range(len(s))]
+        #filling out the diagonal by 1
+        for i in range(len(s)):
+            dp[i][i] = True
+            longest_palindrom = s[i]
+			
+        # filling the dp table
+        for i in range(len(s)-1,-1,-1):
+				# j starts from the i location : to only work on the upper side of the diagonal 
+            for j in range(i+1,len(s)):  
+                if s[i] == s[j]:  #if the chars mathces
+                    # if len slicied sub_string is just one letter if the characters are equal, we can say they are palindomr dp[i][j] =True 
+                    #if the slicied sub_string is longer than 1, then we should check if the inner string is also palindrom (check dp[i+1][j-1] is True)
+                    if j-i ==1 or dp[i+1][j-1] is True:
+                        dp[i][j] = True
+                        # we also need to keep track of the maximum palindrom sequence 
+                        if len(longest_palindrom) < len(s[i:j+1]):
+                            longest_palindrom = s[i:j+1]
+                
+        return longest_palindrom