Question

Write a recursive function block_count(string) to return the number of blocks consisting of the same letter in the given input string. Example.

>>> block_count ('AABBCCBBDDD')

5

>>>block_count ('GGABAA')

4

Answer 1

Code in python (code to copy) with explanation in comments

def block_count(string):
    # base case
    if(len(string)<=1):
        return len(string)
    # recursive case
    # If the first character is same as the second character
    # then the answer to this string is same as the answer to 
    # this string being read from index 1
    if(string[0]==string[1]):
        return block_count(string[1:])
    # If the above is false then the answer is 1 plus the answer to 
    # the string being read from index 1
    else:
        return 1 + block_count(string[1:])

# Print test results to console
print("block_count ('AABBCCBBDDD') = ", block_count('AABBCCBBDDD'))
print("block_count ('GGABAA') = ", block_count('GGABAA'))

python code screenshot

Output Screnshot