MAXSLAM - Editorial

PROBLEM LINK:

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

Author: iceknight1093
Tester: sushil2006
Editorialist: iceknight1093

DIFFICULTY:

Cakewalk

PREREQUISITES:

None

PROBLEM:

Chef has won X Grand Slams. He want to win at least 25, and can win 4 every year.
How many year will he need?

EXPLANATION:

Chef has X Slams now, and wants to reach 25.
That means he needs at least 25-X more of them.

Every year can give four, so the answer is the smallest k such that 4\cdot k \geq 25 - X.
To find this value of k, you can either iterate over k starting from 0, or do a bit of math and notice that:

4\cdot k \geq 25 - X \iff k \geq \frac{25-X}{4}

So, we want the smallest integer that’s at least \frac{25-X}{4}, which by definition is

\text{ceil}\left(\frac{25-X}{4}\right)

Here, \text{ceil} is the ceiling function.

TIME COMPLEXITY:

\mathcal{O}(1) per testcase.

CODE:

Editorialist's code (PyPy3)
x = int(input())
req = 25 - x
print((req + 3) // 4)