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#Matthew Strapp
#5449340
#Lab 1
def left(exp):
return exp[0]
def op(exp):
return exp[1]
def right(exp):
return exp[2]
def isInside(var, e):
if type(e) is tuple:
return isInside(var, left(e)) or isInside(var, right(e))
elif type(e) is str:
return var==e
else:
return -1
def solve(v, e):
if isInside(v, left(e)):
return solving(v, e)
elif isInside(v,right(e)):
newE=(right(e),op(e),left(e))
return solving(v,newE)
#Solving defined on line 52
else:
return None
#Four major solving means
def solvingAdd(v,q):
if isInside(v, left(left(q))):
return left(left(q)), '=', (right(q), '-', right(left(q)))
else:
return right(left(q)), '=', (right(q), '-', left(left(q)))
def solvingSubtract(v,q):
if isInside(v, left(left(q))):
return left(left(q)), '=', (right(q), '+', right(left(q)))
else:
return right(left(q)), '=', (left(left(q)), '-', right(q))
def solvingMultiply(v,q):
if isInside(v, left(left(q))):
return left(left(q)), '=', (right(q), '/', right(left(q)))
else:
return right(left(q)), '=', (right(q), '/', left(left(q)))
def solvingDivide(v,q):
if isInside(v, left(left(q))):
return left(left(q)), '=', (right(q), '*', right(left(q)))
else:
return right(left(q)), '=', (left(left(q)), '/', right(q))
#Dict based off of lecture 13th Sept. 2019
dispatcher={'+':solvingAdd,'-':solvingSubtract,'*':solvingMultiply,'/':solvingDivide}
def solving(v,q):
if left(q) is v:
return q
else:
if op(left(q)) in dispatcher:
newQ=dispatcher[op(left(q))](v,q)
else:
raise ValueError
return solving(v,newQ)
#
# TESTS. Test the equation solver for CSci 1913 Lab 1.
#
# James Moen
# 10 Sep 18
#
# Every test is followed by a comment which shows what must be printed if your
# code works correctly. It also shows how many points the test is worth, for a
# total of 35 possible points.
#
print(isInside('x', 'x')) # True 1 point
print(isInside('x', 'y')) # False 1 point
print(isInside('x', ('x', '+', 'y'))) # True 2 points
print(isInside('x', ('a', '+', 'b'))) # False 2 points
print(isInside('+', ('a', '+', 'b'))) # False 2 points
print(isInside('x', (('m', '*', 'x'), '+', 'b'))) # True 2 points
print(solve('x', (('a', '+', 'x'), '=', 'c')))
# ('x', '=', ('c', '-', 'a')) 2 points
print(solve('x', (('x', '+', 'b'), '=', 'c')))
# ('x', '=', ('c', '-', 'b')) 2 points
print(solve('x', (('a', '-', 'x'), '=', 'c')))
# ('x', '=', ('a', '-', 'c')) 2 points
print(solve('x', (('x', '-', 'b'), '=', 'c')))
# ('x', '=', ('c', '+', 'b')) 2 points
print(solve('x', (('a', '*', 'x'), '=', 'c')))
# ('x', '=', ('c', '/', 'a')) 2 points
print(solve('x', (('x', '*', 'b'), '=', 'c')))
# ('x', '=', ('c', '/', 'b')) 2 points
print(solve('x', (('a', '/', 'x'), '=', 'c')))
# ('x', '=', ('a', '/', 'c')) 2 points
print(solve('x', (('x', '/', 'b'), '=', 'c')))
# ('x', '=', ('c', '*', 'b')) 2 points
print(solve('y', ('y', '=', (('m', '*', 'x'), '+', 'b'))))
# ('y', '=', (('m', '*', 'x'), '+', 'b')) 2 points
print(solve('x', ('y', '=', (('m', '*', 'x'), '+', 'b'))))
# ('x', '=', (('y', '-', 'b'), '/', 'm')) 2 points
print(solve('a', (('b', '+', 'c'), '=', ('d', '*', (('a', '/', 'e'), '-', 'f')))))
# ('a', '=', (((('b', '+', 'c'), '/', 'd'), '+', 'f'), '*', 'e')) 5 points
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