Suppose we have a list of rational numbers. We have to find their product using reduce function. The reduce() function applies a function with two arguments cumulatively on a list of objects from left to right.
So, if the input is like fractions = [(5,3),(2,8),(6,9),(5,12),(7,2)], then the output will be (175, 432) because 5/3 * 2/8 * 6/9 * 5/12 * 7/2 = (5*2*6*5*7)/(3*8*9*12*2) = 2100/5184 = 175/432.
To solve this, we will follow these steps −
- fracs := a new list
- for each f in frac, do
- insert a new fraction object from (numerator, denominator) pair f at the end of fracs
- t := reduce(fracs with function func(x, y) returns x*y)
- return pair of (numerator of t, denominator of t)
Example
Let us see the following implementation to get better understanding
from fractions import Fraction
from functools import reduce
def solve(frac):
fracs = []
for f in frac:
fracs.append(Fraction(*f))
t = reduce(lambda x, y: x*y, fracs)
return t.numerator, t.denominator
frac = [(5,3),(2,8),(6,9),(5,12),(7,2)]
print(solve(frac))Input
[(5,3),(2,8),(6,9),(5,12),(7,2)]
Output
(175, 432)