Write a recursive method called printNumPattern() to output the following number pattern. Given a positive integer as input (Ex:

The answer that is correct is: "a. the economic advantages caused by their production." U.S. industries such as steel, computers, and energy require protection from international competitors to maintain these economic benefits. They are significant contributors to the nation’s GDP, and both the computer and steel sectors create numerous job opportunities within the United States.

DHCP serves as a network management protocol that operates within UDP/IP networks, where a DHCP server automatically allocates an IP Address and other network settings to each device within the network, facilitating their communication with other IP networks. This system allows computers to automatically request IP addresses and networking parameters from their Internet service provider, minimizing the requirement for manual IP assignment by network administrators or users for each device. Without a DHCP server, devices must either be manually assigned an IP address or use an APIPA address, which limits external communication beyond their local subnet.

def sum_1k(M): s = 0 for k in range(1, M+1): s = s + 1.0/k return s def test_sum_1k(): expected_value = 1.0+1.0/2+1.0/3 computed_value = sum_1k(3) if expected_value == computed_value: print("Test is successful") else: print("Test is NOT successful") test_sum_1k() It appears that the hidden portion involves summing (sigma) from 1 to M with the term 1/k. Accordingly, within sum_1k(M), one should iterate from 1 to M to compute and return the sum of the expression. The test_sum_1k() function calculates the expected_value, an accurate hand-calculated value, while computed_value denotes the result of sum_1k(3). The values are then compared and an appropriate message is printed. Finally, invoke test_sum_1k() to observe the result.

Answer:

alphabet = "abcdefghijklmnopqrstuvwxyz"

test_dups = ["zzz","dog","bookkeeper","subdermatoglyphic","subdermatoglyphics"]

test_miss = ["zzz","subdermatoglyphic","the quick brown fox jumps over the lazy dog"]

# From Section 11.2 of: # Downey, A. (2015). Think Python: How to think like a computer scientist. Needham, Massachusetts: Green Tree Press.

def histogram(s):

d = dict()

for c in s:

if c not in d:

d[c] = 1

else:

d[c] += 1

return d

#Part 1 Construct a function, called has_duplicates, that takes a string argument and returns True if there are any repeating characters present. If not, it should return False.

def has_duplicates(stringP):

dic = histogram(stringP)

for key,value in dic.items():

if value>1:

return True

return False

# Execute has_duplicates by building a histogram using the above histogram function. Implement a loop over the items in the test_dups list.

# Display each string and indicate whether it has duplicates based on the has_duplicates function's result for that string.

# For instance, the expected output for "aaa" and "abc" would be shown below. aaa has duplicates abc has no duplicates Display a similar message for each string within test_dups.

print("***Implementation of has_duplicates function***")

for sTr in test_dups:

if has_duplicates(sTr):

print(sTr+": has duplicates")

else:

print(sTr+": has no duplicates")

#Part 2 Develop a function named missing_letters that takes a string argument and returns a new string containing all alphabet letters absent from the input string.

#The letters in the resultant string should be arranged in alphabetical order. Your implementation must utilize the histogram from the previous function and should reference the global alphabet variable directly.

#It should iterate over the alphabet letters to figure out which are missing from the input string.

#The function missing_letters should merge the list of missing letters into a string and return it.

def missing_letters(sTr):

missingLettersList = []

dic = histogram(sTr)

for l in alphabet:

if l not in dic:

missingLettersList.append(l)

missingLettersList.sort()

return "".join(missingLettersList)

#Iterate over the strings in the test_miss list and invoke missing_letters for each one. Present a line for each string outlining the missing letters.

#For example, for the string "aaa", the output should be as follows. aaa is missing letters bcdefghijklmnopqrstuvwxyz

#Should the string encompass all alphabet letters, the output should indicate that it utilizes all the letters.

#For instance, output for the alphabet string itself would be: abcdefghijklmnopqrstuvwxyz uses all the letters

#Generate a similar line for each item in test_miss.

print("\n***Implementation of missing_letters function***")

for lTm in test_miss:

sTr = missing_letters(lTm.replace(" ",""))

if sTr!="":

print(lTm+" is missing letters "+sTr)

else:

print(lTm +" uses all the letters")