Python program to find number of likes and dislikes

Alice and Bob made a list of topics and both of them voted if they like or dislike the topic. They wrote 0 to denote dislike and 1 to denote like. The task is to count the number of topics that both of them like or dislike.


Input: alice = “010101” bob = “101101”
Output: 3
alice and bob both like 4th and 6th topics and dislike the 5th topic. Hence, the output is 3.

Input: alice = “111111” bob = “000000”
Output: 0
There are no common likes or dislikes between alice and bob. Hence, the output is 0.

Input: alice = “110000” bob = “110011”
Output: 4
alice and bob both like 1st and 2nd topics and dislike 3rd and 4th topics. Hence, the result is 4.


  • First, we have to iterate through each character of the string consisting of the likes and dislikes of alice.
  • Then, we have to compare it with the corresponding entry of the string consisting of the likes and dislikes of bob.
  • Finally, we will count the number of similar entries and print.

Below is the implementation.





# function to obtain no 
# of topics both alice and 
# bob like 
def commontopics(alice, bob):
    # initiate count with 0
    count = 0
    # iterating through alice
    for i in range(0,len(alice)):
        # comparing with corresponding
        # bob entry
        if alice[i] == bob[i]:
            # counting similar entries
            count += 1 
    # printing the count         
#main function 
def main():
    commontopics("010101", "101101")
    commontopics("111111", "000000")
    commontopics("110000", "110011")
# driver code
if __name__ == "__main__":
# This code is contributed by SrujayReddy



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