programming hw

# SAMS 2018, Programming Sections A and B
#########################################
# Full name:
# Andrew ID:
#########################################

# DUE DATE: Sunday July 8th, 5pm
# SUBMIT THIS FILE TO AUTOLAB. LATE SUBMISSIONS WILL NOT BE ACCEPTED.

# For the functions below, erase the "return 42" line and write the
# appropriate piece of code instead.

# You will need the following function to compare floats
def almostEqual(d1, d2):
    epsilon = 10**-8
    return (abs(d2 - d1) < epsilon)


#### PROBLEM 1 ####

# Given an integer n, return True if n is even and return False otherwise.
# Hint: use the % operator.
def isEven(n):
    m= n % 2
    if (m==0):
        return True
    else:
        return False

#### PROBLEM 2 ####

# Given an integer n, return the ones-digit of n,
# i.e. the first digit of n from the right.
def onesDigit(n):
    if n < 0:
       n=n*-1
    n=n/10
    n=n%1
    n=10*n
    return int(n)

# Given an integer n, return the tens-digit of n,
# i.e. the 2nd digit of n from the right.
def tensDigit(n):
    if n < 0:
        n=n*-1
    n=n//10
    n=n%10
    return int(n)

# Given an integer n and k, return the (k+1)'th digit of n from the right.
# So k = 0 refers to the ones-digit, k = 1 refers to the tens-digit, etc.
# You can assume k is non-negative.
def getKthDigit(n, k):
    n=abs(n)
    n=n/(10**k)
    n=n//1
    n=n%10
    return int(n)

# Given integers n, k and d, replace the kthDigit of n with d.
# You can assume k is non-negative, and d is an integer between 0 and 9.
# NOTE: It may help to do problems 3 and 4 and then come back to this one!
def getKthDigit(n, k):
    n=abs(n)
    n=n/(10**k)
    n=n//1
    n=n%10
    return int(n)
def setKthDigit(n, k, d):
    n= ((d-getKthDigit(n,k))*(10**k)+n)
    return (n)


#### PROBLEM 3 ####

# Given a float n, round it down to the nearest integer.
# You are not allowed to use anything from the math module.
def floor(n):
    if n>0:
        n=n//1

#### PROBLEM 4 ####

# Given a non-negative int street, return the nearest bus stop to the given
# street, assuming buses stop every 8th street, including street 0, with ties
# going to the lower street.  Thus, the nearest bus stop to 12th street is
# 8th street, and the nearest bus stop to 13th street is 16th street.
def nearestBusStop(street):
    if n>4
        return (n-(n%8)+8)
    else
        return n-(n%8)

#### PROBLEM 5 ####

# Write the function threeLinesArea(m1, b1, m2, b2, m3, b3) that takes
# six int or float values representing the 3 lines:
#   y = m1*x + b1
#   y = m2*x + b2
#   y = m3*x + b3
# finds where each pair of lines intersects, then returns the area of the
# triangle formed by connecting these three points of intersection.
# If no such triangle exists (if any two of the lines are parallel), return 0.

# To do this, you must write three helper functions: one to find where two
# lines intersect (which you will call three times), a second to find the distance
# between two points (see above), and a third to find the area of a triangle given
# its side lengths (which you will call once). You may write other helper functions
# if you think they would be useful, but you must at least write these three exactly
# as described below, and then you must use them appropriately in your solution.
# Of course, you should write and test the helper functions first before writing
# this function (that's why they are helper functions - to break down this function
# into smaller, more manageable (and testable) chunks.
def threeLinesArea(m1, b1, m2, b2, m3, b3):
    return 42

# This function takes four int or float values representing two lines and returns
# the x value of the point of intersection of the two lines. If the lines are
# parallel, or identical, the function should return None.
def lineIntersection(m1, b1, m2, b2):
    return 42

# returns the distance between 2 points using the formula:
# distance equals the square root of the sum of the squares of the
# difference between the two x coordinates and the two y coordinates
def distance(x1, y1, x2, y2):
    return 42

# This function takes three int or float values representing side lengths of a
# triangle, and returns the area of that triangle. To do this, you may wish to
# use Heron's Formula (time to use Google).
def triangleArea(s1, s2, s3):
    return 42


# If you have written the functions correctly, you should not get any errors
# when you run this file, i.e., you should pass all the tests below.


######################################################################
# ignore_rest: The autograder will ignore all code below here
######################################################################

import math

def testIsEven():
    print("Testing isEven()...", end="")
    assert(isEven(0))
    assert(not isEven(1))
    assert(isEven(2))
    assert(not isEven(3))
    assert(isEven(4))
    assert(not isEven(-1))
    assert(isEven(-2))
    assert(not isEven(-3))
    assert(isEven(-4))
    assert(isEven(123456))
    print("Passed.")

def testOnesDigit():
    print("Testing onesDigit()...", end="")
    assert(onesDigit(0) == 0)
    assert(onesDigit(789) == 9)
    assert(onesDigit(7) == 7)
    assert(onesDigit(-1234) == 4)
    assert(onesDigit(-3) == 3)
    print("Passed.")

def testTensDigit():
    print("Testing tensDigit()...", end="")
    assert(tensDigit(0) == 0)
    assert(tensDigit(1) == 0)
    assert(tensDigit(10) == 1)
    assert(tensDigit(21) == 2)
    assert(tensDigit(-1234) == 3)
    assert(tensDigit(-3) == 0)
    assert(tensDigit(-10) == 1)
    print("Passed.")

def testGetKthDigit():
    print("Testing getKthDigit()...", end="")
    assert(getKthDigit(0,0) == 0)
    assert(getKthDigit(789, 0) == 9)
    assert(getKthDigit(789, 1) == 8)
    assert(getKthDigit(789, 2) == 7)
    assert(getKthDigit(789, 3) == 0)
    assert(getKthDigit(-1234, 3) == 1)
    assert(getKthDigit(-3, 1) == 0)
    print("Passed.")

def testSetKthDigit():
    print("Testing setKthDigit()...", end="")
    assert(setKthDigit(468, 0, 1) == 461)
    assert(setKthDigit(468, 1, 1) == 418)
    assert(setKthDigit(468, 2, 1) == 168)
    assert(setKthDigit(468, 3, 1) == 1468)
    assert(setKthDigit(777, 2, 7) == 777)
    assert(setKthDigit(-468, 1, 5) == -458)
    print("Passed.")

def testFloor():
    print("Testing floor()...", end="")
    assert(floor(0) == math.floor(0))
    assert(floor(1) == math.floor(1))
    assert(floor(-1) == math.floor(-1))
    assert(floor(1.1) == math.floor(1.1))
    assert(floor(1.5) == math.floor(1.5))
    assert(floor(1.9) == math.floor(1.9))
    assert(floor(-1.1) == math.floor(-1.1))
    assert(floor(-1.5) == math.floor(-1.5))
    assert(floor(-1.9) == math.floor(-1.9))
    assert(floor(0.1) == math.floor(0.1))
    assert(floor(0.5) == math.floor(0.5))
    assert(floor(0.9) == math.floor(0.9))
    assert(floor(-0.1) == math.floor(-0.1))
    assert(floor(-0.5) == math.floor(-0.5))
    assert(floor(-0.9) == math.floor(-0.9))
    print("Passed.")

def testNearestBusStop():
    print("Testing nearestBusStop()...", end="")
    assert(nearestBusStop(0) == 0)
    assert(nearestBusStop(4) == 0)
    assert(nearestBusStop(5) == 8)
    assert(nearestBusStop(12) == 8)
    assert(nearestBusStop(13) == 16)
    assert(nearestBusStop(20) == 16)
    assert(nearestBusStop(21) == 24)
    print("Passed.")

def testLineIntersection():
    print("Testing lineIntersection()...", end="")
    assert(lineIntersection(2.5, 3, 2.5, 11) == None)
    assert(lineIntersection(25, 3, 25, 11) == None)
    # y=3x-5 and y=x+5 intersect at (5,10)
    assert(almostEqual(lineIntersection(3,-5,1,5), 5))
    # y=10x and y=-4x+35 intersect at (2.5,25)
    assert(almostEqual(lineIntersection(10,0,-4,35), 2.5))
    print("Passed.")

def testDistance():
    print("Testing distance()...", end="")
    assert(almostEqual(distance(0, 0, 1, 1), 2**0.5))
    assert(almostEqual(distance(3, 3, -3, -3), 6*2**0.5))
    assert(almostEqual(distance(20, 20, 23, 24), 5))
    print("Passed.")

def testTriangleArea():
    print("Testing triangleArea()...", end="")
    assert(almostEqual(triangleArea(3,4,5), 6))
    assert(almostEqual(triangleArea(2**0.5, 1, 1), 0.5))
    assert(almostEqual(triangleArea(2**0.5, 2**0.5, 2), 1))
    print("Passed.")

def testThreeLinesArea():
    print("Testing threeLinesArea()...", end="")
    assert(almostEqual(threeLinesArea(1, 2, 3, 4, 5, 6), 0))
    assert(almostEqual(threeLinesArea(0, 7, 1, 0, -1, 2), 36))
    assert(almostEqual(threeLinesArea(0, 3, -.5, -5, 1, 3), 42.66666666666))
    assert(almostEqual(threeLinesArea(1, -5, 0, -2, 2, 2), 25))
    assert(almostEqual(threeLinesArea(0, -9.75, -6, 2.25, 1, -4.75), 21))
    print("Passed.")


def testAll():
    testIsEven()
    testOnesDigit()
    testTensDigit()
    testGetKthDigit()
    testSetKthDigit()
    testFloor()
    testNearestBusStop()
    testLineIntersection()
    testDistance()
    testTriangleArea()
    testThreeLinesArea()


testAll()