"""
Exercise 7 (fun_exercise_7)
The function takes in input a list of strings x and returns an integer ptr if and only if x[ptr]
is a substring of at least one of the other strings in x. Otherwise, it returns -1.

ptr is a pointer

if one string is a substring of another, then return the position of the substring as ptr

################################
my idea:

so what i would do is use a while i < len(x) loop to find out if
x[y] is substring of x[z], return y
is x[y] a substring of x[z+1]?
keep increasing the z until either a substring has been found, or until list has been completely indexed;
if this is the case then increase x[y] by 1
increase x[y] and repeat the same operation
until the list has been completely searched
if still no matches, return -1
"""


def fun_exercise_7(x):
    for ptr in range(len(x)):
        for str in x:
            if x[ptr] != str:
                if str in x[ptr]:
                    return ptr
    return -1



    #

print(fun_exercise_7(["goat"]))  # -1
print(fun_exercise_7(["soul", "soulmate", "origin"]))  # 0
print(fun_exercise_7(["FASER", "submission", "online", "drive", "frequent"]))  # -1
print(fun_exercise_7(["banana", "applejuice", "kiwi", "strawberry", "apple", "peer"]))  # 4