Codeforces: A. Is your horseshoe on the other hoof?

ACMer

13 years ago

228A Codeforces: A. Is your horseshoe on the other hoof? beginner codeforces implementation math mysql programming languages python tricks

The answer is to count the unique number of integers and substract from four. The SQL to the answer is:

select 4 - count(distinct `numbers`) from input

Using Python set (that automatically removes duplicated elements), the answer can be easily obtained.

#!/usr/bin/env python
print 4 - len(set(raw_input().split()))

Python supports union, disjoin, intersection operations on sets. For example,

>>> a=set([1,2,3,4])
>>> b=set([2,3,4,5])
>>> a&b
set([2, 3, 4])
>>> a-b
set([1])
>>> b-a
set([5])
>>> a|b
set([1, 2, 3, 4, 5])