Homework 3

Homework 3


Note: For this homework you are only allowed to use concepts and functions taught in the class. For
example you are NOT allowed to use set() , intersection() etc For taking the input lists you can use .split()
to get the individual numbers.
Q1. 30 points
Given two lists of numbers output the numbers which are in both lists.
Note: You may assume no numbers are repeated within a single list
Sample output:
Please enter a list of numbers:
1 5 2 3
Please enter a second list of numbers:
5 6 1
The numbers in both lists are: 1 5
Q2. 30 points
Given two lists of numbers output the numbers which are in one list or the other.
Sample output:
Please enter a list of numbers:
1 5 2 3 1 3
Please enter a second list of numbers:
5 6 1
The numbers in one list or the other are: 1 5 2 3 6
Q3. 40 points
Take a string from the user and output if it a valid variable name. A variable name is valid if it contains
only alphabets, numbers and the underscore character. Additionally it can not start with a number
Sample output I:
Please enter a variable name: abc_123
abc123 is valid
Sample output II:
Please enter a variable name: 1ab
1ab is not valid
Sample output III:
Please enter a variable name: abc___d
abc___d is valid
Sample output IV:
Please enter a variable name: abc%$d
Abc%$d is not valid
Q4. Extra credit 30 points
You are given n and a list of numbers which contain the numbers 1 through n with one of them
repeated. Output which number is repeated without using .count()
Note: for this question checking if a number j is in a list lst twice by using the lst.count(j) == 2 is not
allowed. You have to write your own code to perform this check if you intend to use it
An additional 20 points if you can do this using a single loop
Sample output I:
Please enter n: 5
Please enter the list: 1 2 5 4 3 3
The repeated number is 3
Sample output II:
Please enter n: 4
Please enter the list: 2 3 4 1 2
The repeated number is 2
Sample output III:
Please enter n: 7
Please enter the list: 5 4 7 3 1 2 6 3
The repeated number is 3