Consider the following Python code that returns true if and only if the string s is a palindrome. A string is a palindrome if it is the same when reversed, e.g., "madam" is a palindrome whereas "algorithm" is not.

def is_palindrome(s):
   left = 1
   right = len(s)

   while left

Question

Consider the following Python code that returns true if and only if the string s is a palindrome. A string is a palindrome if it is the same when reversed, e.g., "madam" is a palindrome whereas "algorithm" is not.

def is_palindrome(s): 
       left = 1 
       right = len(s) 
   
       while left < right: 
              # loop invariant 
             if s[left] != s[right]: 
                   return False 
              left += 1 
              right -= 1 
       return True 
 What is an appropriate loop invariant for this algorithm at the point specified?

Accepted Answer

the string s[1...left-1] is the same as the reverse of the string s[right+1...len(s)].

Answer

the string s[1...left] is the same as the string s[right...len(s)].

Answer

the string s[1...left-1] is the same as the string s[right+1...len(s)].

Answer

the string s[1...left] is the same as the reverse of the string s[right...len(s)].

Crowdly

Consider the following Python code that returns true if and only if the string s...

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