catCount.py

mystery_string = "my cat your cat"

# Add some code below that will count and print how many
# times the character sequence "cat" appears in mystery_string.
# For example, for the string above, it would print 2.
#
# This one is tricky! Think carefully about for-each loops,
# conditionals, and booleans. How can you track what character
# you're currently looking for? We expect you'll use a loop
# and a single big conditional, but there are other approaches
# as well. Try to stick with the topics we've covered so far.

# Initialize the count variable
cat_count = 0

# Loop through the string, checking for the substring "cat"
for i in range(len(mystery_string) - 2):
    if mystery_string[i:i + 3] == "cat":
        cat_count += 1

# Print the result
print(cat_count)


count = 0

# Next, we need to keep track of what letter we're currently
# searching for. The first letter in "cat" is "c", so by
# default, we'll set this to "c":
current_search_letter = "c"

# Then, we loop over all the letters in the string:
for letter in mystery_string:

    # For each letter, we want to see if it's the letter
    # we're looking for.
    #
    # If it's a 'c' and we're looking for 'c', great! Now
    # we're looking for 'a':
    if letter == "c":
        current_search_letter = "a"

    # If it's an 'a' and we're looking for 'a', great! Now
    # we're looking for 't':
    elif letter == "a" and current_search_letter == "a":
        current_search_letter = "t"

    # If it's a 't' and we're looking for 't', then we've
    # found the word 'cat'! So, we add one to the counter,
    # and start over looking for 'c' again:
    elif letter == "t" and current_search_letter == "t":
        count += 1
        current_search_letter = "c"

    # Here's the trick: if we find any letter other than the
    # one we were looking for, then we need to start over!
    # If we've found "ca" but the next letter is "b", then
    # it doesn't matter if the one after it is "t": "cabt"
    # isn't the same as "cat":
    else:
        current_search_letter = "c"
print(count)