Programming 1
Week 8: Exercises

1. Time Class

Write a class Time that represents a time of day with 1-second resolution, e.g. 11:32:07.

• Include a static method make that takes three integers (hours, minutes, seconds) and returns a Time. Seconds should default to 0 if not provided.

• The '+' operator should add a number of seconds to a Time, yielding a new Time object (wrapping past midnight if necessary).

• The '-' opertator should subtract two Time objects, yielding a (possibly negative) number of seconds.

• A Time object's string representation should look like this: "11:32:07".

2. Vector Class

Write a class Vector that represents a vector in n-dimensional space.

• Provide an initializer that takes a list of numbers, yielding a vector with those components.

• The '+' operator should add two vectors.

• The '*' operator should multiply a scalar times a vector, yielding a new vector.

• The '*' operator should compute the dot product of two vectors, yielding a scalar.

• Provide a method v.length() that computes the length of a vector.

• Provide a method v.angle(w) that computes the angle between two vectors in radians.

• A vector should have a string representation such as "[3.25 5.02 -6.12]", with two digits after the decimal point in each component.

3. Delete All Odd

You are given a class LinkedList with a single attribute head that points to the head of a linked list. Each list node is an instance of the Node class:

class Node:
  def __init__(self, val, next):
    self.val = val
    self.next = next
    
class LinkedList:
  def __init__(self, head):
    self.head = head

Write a method that deletes all odd values from a LinkedList of integers.