Write the Big$-$O notation next to the function for each subquestion below.

a$.$

# Assume s is a string with n characters

def f$($s$)$:

if s $==""$:

return $""$

print$($s$[$:len$($s$)//2])$

return f$($s$[$:len$($s$)//2])$

b$.$

# Assume s is a string with n characters

def f$($s$)$:

x $=$ len$($s$)$

y $=$ s

while x $>0$:

s $=$ y

while len$($s$)>0$:

s $=$ s$[$:len$($s$)//2]$

x $=$ x $-1$

c$.$

# Assume n is a positive integer

def f$($n$)$:

for i in range$($n$)$:

print$($i$)$

for j in range$($n$)$:

print$($j$)$

for k in range$(10)$:

print$($k$)$

d$.$

# Assume aList is list containing n items

def f$($aList$)$:

for i in range$($len$($aList$)-1,0,-2)$:

for j in range$($i$)$:

print$($i$,$ j$)$

e$.$

# Assume n is a positive integer

def f$($n$)$:

if n $<500$:

return f$($n$*3)$