CWSS 2020 Computing P2 Solution

MARKING SCHEME Question Answer Marks Task 1 1 =LEFT(A4,1) 1 2 =HLOOKUP(D4,$K$5:$O$6,2,TRUE) (1 mark for HLookup, 1 mark for correct arguments) 2 3 =F4*E4 1 4 =IF(G4>75,"YES","NO") (1 mark for using IF, 1 mark for correct condition 2 5 1 mark for condition, 1 mark for formatting 2 6 =COUNTIF(C$4:C$22,"N") (1/2 mark for each correct function) 2 Task 2 7 ID = '' count_SG = 0 for i in range(5): ID = input("Enter ID: ") if ID[0] == "S" or ID[0] == "T": print("Welcome home!") count_SG += 1 else: print("Welcome to Singapore!") print("Number of Singaporeans returning home: ", count_SG) 8 ID = '' count_SG = 0 num = int(input("Enter number of entries: ")) for i in range(num): ID = input("Enter ID: ") while len(ID)!= 9: ID = input("Incorrect length. Please enter again:") if ID[0] == "S" or ID[0] == "T": print("Welcome home!") count_SG += 1 else: print("Welcome to Singapore!") print("Number of Singaporeans returning home: ", count_SG)

2 Question Answer Marks Task 3 9 string = input("Enter string: ") index = int(input("Enter the index/indices of characters you wish to extract in a,b,c format: ")) indx_lst == index.split("") new_string = '' final_string = '' for j in range(string): if string[j] == '': break else: new_string = new_string + string[j] for i in range(len(indx_lst)): indx_lst[i] = indx_lst[i] for ele in range(indx_lst): final_string = final_string + new_string[ele] print("The original sentence is: , string") print("The index/indices of characters you wish to extract is/are ", indx_lst) print("The character(s) extracted is/are ", final_string) index = input("Enter the index/indices of characters you wish to extract in a,b,c format: ") indx_lst = index.split(",") for j in range(len(string)): if string[j] == ' ': continue indx_lst[i] = int(indx_lst[i]) for ele in indx_lst: print("The original sentence is: ", string) Task 4 10 Input marks in proper format variables set up and initialised for grades variables set up and initialised for number of distinction, credit, pass and failure use of loop till entry = x Conversion of raw marks into corresponding grade correct calculation of number of distinction, credit, pass and failures

3 Question Answer Marks Correct display with format 11 Validation of length = 4 Validation for marks to be between 0 and 100 Re-entries of grades if fail 12 Screenshot: Correct output File in png or jpg format 13 Extend: input of distinction mark, credit mark and passing mark Validation of distinction mark higher than the other two marks, and credit marks higher than passing mark

4 SOLUTIONS Task 2 (MYVERIFY.py) ID = '' count_SG = 0 for i in range(5): ID = input("Enter ID: ") if ID[0] == "S" or ID[0] == "T": print("Welcome home!") count_SG += 1 else: print("Welcome to Singapore!") print("Number of Singaporeans returning home: ", count_SG) (NUMVERIFY.py) ID = '' count_SG = 0 num = int(input("Enter number of entries: ")) for i in range(num): ID = input("Enter ID: ") while len(ID)!= 9: ID = input("Incorrect length. Please enter again:") if ID[0] == "S" or ID[0] == "T": print("Welcome home!") count_SG += 1 else: print("Welcome to Singapore!") print("Number of Singaporeans returning home: ", count_SG)

5 Task 3 (LIST.py) string = input("Enter string: ") index = input("Enter the index/indices of characters you wish to extract in a,b,c format: ") indx_lst = index.split(",") new_string = '' final_string = '' for j in range(len(string)): if string[j] == ' ': continue else: new_string = new_string + string[j] for i in range(len(indx_lst)): indx_lst[i] = int(indx_lst[i]) for ele in indx_lst: final_string = final_string + new_string[ele] print("The original sentence is: ", string) print("The index/indices of characters you wish to extract is/are ", indx_lst) print("The character(s) extracted is/are ", final_string)

6 Task 4 (GRADES.py) grades = [] dist, credit, passes, fail = 0,0,0,0 while True: marks = input("Enter the marks for EL, MT, Math and Sci: ").split(' ') if marks[0] == 'x': break else: validity = True for i in range(len(marks)): marks[i] = int(marks[i]) if marks[i] >= 75: grades.append("D") elif marks[i] >= 65: grades.append("C") elif marks[i] >= 50: grades.append("P") else: grades.append("F") print("\n\nGrades for \t EL \t MT \t Math \t Sci") for j in range (0,len(grades)-1,4): print("\t\t", grades[j],"\t", grades[j+1],"\t",grades[j+2],"\t",grades[j+3]) for k in range(len(grades)): if grades[k] == "D": dist +=1 elif grades[k] == "C": credit +=1 elif grades[k] == "P": passes +=1 else: fail +=1 print("\n\nNumber of distinctions: \t", dist) print("Number of credits: \t\t", credit) print("Number of passes: \t\t", passes) print("Number of failures: \t\t", fail)

7 (VERIFYGRD.py) grades = [] dist, credit, passes, fail = 0,0,0,0 while True: marks = input("Enter the marks for EL, MT, Math and Sci: ").split(' ') if marks[0] == 'x': break else: validity = True if len(marks) == 4: for i in range(len(marks)): marks[i] = int(marks[i]) if marks[i] > 100 or marks[i] < 0: print("Error, marks should be between 0 and 100 inclusive") validity = False else: print("Error, there should only be 4 entries") validity = False if validity == True: for j in range(len(marks)): if marks[j] >= 75: grades.append("D") elif marks[j] >= 65: grades.append("C") elif marks[j] >= 50: grades.append("P") else: grades.append("F") print("\n\nGrades for \t EL \t MT \t Math \t Sci") for j in range (0,len(grades),4): print("\t\t", grades[j],"\t", grades[j+1],"\t",grades[j+2],"\t",grades[j+3]) for k in range(len(grades)): if grades[k] == "D": dist +=1 elif grades[k] == "C": credit +=1 elif grades[k] == "P": passes +=1 else: fail +=1 print("\n\nNumber of distinctions: \t", dist) print("Number of credits: \t\t", credit) print("Number of passes: \t\t", passes) print("Number of failures: \t\t", fail)

8 (VARYGRD.py) grades = [] dist, credit, passes, fail = 0,0,0,0 all_pass = False while all_pass == False: dist_mark = int(input("Enter distinction mark:")) cred_mark = int(input("Enter credit mark:")) pass_mark = int(input("Enter pass mark:")) if dist_mark > cred_mark and cred_mark > pass_mark: all_pass = True else: print("Error! Distinction mark may be lower than credit mark or credit mark is lower than pass mark") while True: marks = input("Enter the marks for EL, MT, Math and Sci: ").split(' ') if marks[0] == 'x': break else: validity = True if len(marks) == 4: for i in range(len(marks)): marks[i] = int(marks[i]) if marks[i] > 100 or marks[i] < 0: print("Error, marks should be between 0 and 100 inclusive") validity = False else: print("Error, there should only be 4 entries") validity = False if validity == True: for j in range(len(marks)): if marks[j] >= dist_mark: grades.append("D") elif marks[j] >= cred_mark: