"""
This program:
- asks the user to enter two strings, string1 and string2.
- finds all positions in string1 where string2 occurs.
- prints out those positions and the total number of such positions.

Note: overlapping occurrences of string2 are NOT discarded.

For example, if string1 = "abcIOIOIOIOIOabc" and string2 is "IOIOIO",
the program will report that string2 appears 3 times in string1.
"""

string1 = input("enter the first string: ")
string2 = input("enter the second string: ")

# temp_string starts off equal to string1, and becomes a more and more
# truncated version of string1. Every time we find string2 in temp_string,
# we truncate the start of temp_string up to (and including) the first
# character of the occurrence of string2.
temp_string = string1
count = 0
positions = []
adjustment = 0

# go through the first string, looking for occurrences of the second string
while True:
    # find next position
    position = temp_string.find(string2)
    if position == -1:
        break
    
    count = count + 1
    positions.append(position + adjustment)

    # truncate the start of temp_string, to strip off the
    # occurrence of string2 that we just found
    temp_string = temp_string[position+1:]

    # adjustment remembers how many total characters we have truncated
    # from string1 to obtain the current version of temp_string
    # this is important so that we can convert the position of string2
    # in temp_string into the corresponding position of string2 in string1.
    adjustment = adjustment + position + 1

print("The second string appears in the first string", count, "times.")
print("positions:", positions)