DIVIDE3 - Editorial

PROBLEM LINK:

Practice
Contest: Division 1
Contest: Division 2
Contest: Division 3
Contest: Division 4

Author: raysh07
Tester: sushil2006
Editorialist: iceknight1093

DIFFICULTY:

Cakewalk

PREREQUISITES:

None

PROBLEM:

You have N toffees, which must be divided between 3 friends.
Find the minimum possible imbalance of the distribution, i.e. the difference between the maximum and minimum toffees.

EXPLANATION:

If N is a multiple of 3, you can give each friend \frac{N}{3} toffees, which makes the imbalance 0.

If N is not a multiple of 3, it’s obviously impossible to achieve an imbalance of 0.
However, in this case it’s always possible to achieve an imbalance of 1.

A simple strategy to do this is to just distribute toffees cyclically - that is, give one toffee to friend 1, then one toffee to friend 2, then one to friend 3, then go back to friend 1 and repeat.

So, quite simply,

  • If N is a multiple of 3, the answer is 0.
  • Otherwise, the answer is 1.

Checking whether N is a multiple of 3 can be done using the % operator in most languages.
Alternately, you can use the N \leq 10 constraint to only check whether N equals one of 3, 6, or 9.

TIME COMPLEXITY:

\mathcal{O}(1) per testcase.

CODE:

Editorialist's code (PyPy3)
n = int(input())
if n%3 == 0: print(0)
else: print(1)